Assignment #02
Objectives
Objectives are specified in the assignment where the relevant situation is first encountered,
and will typically be revisited during subsequent assignments,
in the completion of which mastery is expected to build.
02.01.
Identify and explain in terms of a simple example the
proportionalities among dQ/dt (rate of thermal energy transfer), L
(distance between points on a flow line), A_cs (cross-sectional area
of flow) and `dT/`dx (temperature gradient).
Technically:
Relate
{dQ/dt, k,
L, A_cs, dT/dx,
T_1, T_2}
Introductory Problem Set, class notes
02.02.
Identify and explain in terms of a simple example the
proportionalities among L_0 (the original length of an object), `dL
(the change in its length due to thermal expansion), A_0 (original
surface area), `dA (change in surface area), V_0 (original volume),
`dV (chagne in volume) and `dT (the change in its temperature).
Technically:
Relate
{`dL, L_0, `dT,
T_0, T_f, alpha, A_0, `dA,
V_0, `dB, beta}
Introset, class
notes
02.03.
Apply the definition of specific heat to determine the
quantities required to calculate it, observe those quantities
and determine the specific heat.
Technically:
02.03
Relate
-
c
(specific heat of an object)
-
m
(mass of the object)
-
`dQ
(change in thermal energy of the object)
-
`dT
(change in temperature of the object)
-
T_0 (initial temperature of the object)
-
T_f (final temperature of the object)
System 5a (cylinder and mass(es) (BB’s)
at vel v, elastic)
02.09. Apply the definition of thermal conductivity to the
flow of thermal energy through a wall or a bar.
Technically:
-
Relate
{x_0, x_1, T_0, T_1, k, A, `dL, `dT, temperature
gradient}
02.10.
|
Asst #02 |
Introductory Problem Set |
lab/activity |
text |
outline |
Class Notes |
other |
query |
|
02 |
Set 5, Probs 10-13 |
General College Physics and University Physics students do
Flow Experiment [2]
Brief Bottlecap and Tube Setups [3]
Formatting Guidelines and Conventions [2]
PHeT
11.9 Gas Properties |
text_02 |
|
Class Notes
#03 |
|
query_2
therm
energy transfer, expansion (proportionalities)
univ
calorimetry
B7.
volumes |
|
Assignment #03
Objectives:
System 1a:
03.01.
Relate,
where T_1 and T_2 are the initial temperatures of equal amounts
of gas and T_f the final temperature when mixed; gas pressure
constant
03.02.
Relate,
for two samples of gas in a divided container at equal pressure,
where T, V, n, m are absolute temperature,
volume, number of moles and mass,
-
{T_1, V_1, T_2, V_2, n_1, n_2, m_1,
m_2, T_f}
03.03.
Relate,
for two samples of the same gas in a divided container
-
{V_1, V_2, T_1, T_2, P_1, P_2,
T_f}
03.04.
Relate,
for a confined gas
03.05.
Relate,
for a confined gas
-
{P_0, T_0, V_0, N_0, P_f,
T_f, V_f,
N_f}
All of the above objectives are addressed in the Introductory
Problem Set assignments and the text assignment.
|
Asst #03 |
Introductory Problem Set |
lab/activity |
text |
outline |
Class Notes |
other |
query |
|
03 |
Set 5, Probs 14-16
|
Temperature vs. Clock Time Measurements [2]
Are Your Labs Posted in Readable Format? [1] |
text_03 |
|
|
|
query_3
calorimetry,
temp scales, gas laws
univ
radiation
B9. surface
areas _ misc |
|
Assignment #04 Objectives
04.01. Apply the definition of specific heat to calorimetry problems.
Technically:
04.01.
Relate
for an isolated collection of n objects, where the subscript i
refers to the i_th object, 1 <= i <= n
-
c_i
(specific heat of the i_th object)
-
m_i
(mass of the i_th object)
-
`dQ_i
(change in thermal energy of the i_th
object)
-
`dT_i
(change in temperature of the i_th
object)
-
T_0_i (initial temperature of the i_th object)
-
T_f (final temperature of the system)
text
|
Asst #04 |
Introductory Problem Set |
lab/activity |
text |
outline |
Class Notes |
other |
query |
|
04 |
|
Brief Bottle Experiments [2]
Experiments to View |
text_04 |
|
Class Notes
#04 |
|
query_4
gas laws, energy equiv of thermal energy,
univ
rms vel,
Units of Volume Measure |
|
Assignment #05
Objectives
System 4:
05.01. Observe for a system consisting of a
confined gas in a bottle which also contains some water and a
tube leading from the water to the surrounding atmosphere how
the cross-sectional area of the tube, the volume of gas
in the bottle, the volume of water displaced into the tube, and
the change in the water level in the tube vary as the bottle is
squeezed.
Technically:
05.01.
Relate
for a capped-bottle system with an open tube, where A_cs is the
cross-sectional area of the tube, V_bottle the volume of the gas in
the bottle,
`dV_tube the volume of water displaced into the tube, `dy the change
in the water level in the tube.
-
{A_cs,`dL,
V_bottle, `dV_tube,
`dV_tube/V_bottle
, `dV_tube/V_bottle
(as %), `dy }
05.02. Observe for a system consisting of a
confined gas in a bottle which also contains some water and a
tube leading from the water to the surrounding atmosphere how
the pressure inside the bottle, the change in the water level in the
tube, the perceived force exerted when squeezing the bottle,
atmospheric pressure, the absolute temperature of the gas, the
initial volume of the bottle, and the change in volume
vary as the bottle is squeezed.
Technically:
05.02.
Relate
for a capped-bottle system with an open tube, where P is the
pressure inside the bottle, `dy the change in the water level in the
tube, squeeze is perceived force exerted when squeezing the bottle,
P_atm, T the absolute temperature of the gas, V the initial volume
of the bottle, `dV the change in volume ..
-
{P, `dy, squeeze}
-
{P, `dy, squeeze,
P_atm}
-
{P, `dy, squeeze,
P_atm,T, V, `dV}
05.03.
Relate
for a cylinder floating at equilibrium in a body of water
with its axis vertical:
- depth of bottom of cylinder
- pressure at bottom of cylinder
- cross-sectional area of cylinder
- vertical force exerted by pressure on cylinder
- volume of submerged portion of cylinder
- weight of water if cylinder was full of water
- net force on cylinder
- buoyant force
05.04.
Relate
for cylindrical water 'plug' of length `dL and
cross-sectional area A_exit (cylinder axis horizontal)
corresponding to area of outflow hole at depth y:
- water pressure
- depth
- net force on 'plug'
- work on 'plug' as it exits through hole
- volume of 'plug'
- mass of 'plug'
- exit velocity of plug if no energy dissipated
- potential energy change of system from before exit to
after exit of 'plug'
05.05.
Relate
for any object immersed or partially immersed in a fluid
- buoyant force
- weight
- density of fluid
- density of object
- volume of object
- volume of submerged part of object
- volume of water displaced
- mass of object
- mass of submerged part of object
- mass of water displaced
- weight of object
- weight of submerged part of object
- weight of water displaced
- force exerted by gravity on object
- net force on object
- forces on object other than gravitational or buoyant
05.07.
Relate
for a bottle-and-cap system with a vertical tube and a
pressure tube between two states
- initial and final fluid level in vertical tube
- initial and final lengths of air column in pressure tube
- density of fluid
- volume ratio for air column in pressure tube
- excess pressure necessary to support excess fluid in
vertical tube
- atmospheric pressure
- volume ratio of confined gas
- temperature ratio of confined gas
All objectives are addressed in the Introset, lab
exercise, text and Class Notes for this assignment.
|
Asst 05 |
Introductory Problem Set |
lab/activity |
text |
outline |
Class Notes |
other |
query |
|
05 |
Set 5, Probs 1-3 |
Raising Water in a Vertical Tube [2] |
text_05 |
|
Class Notes
#05 |
|
query_5
|
|
Assignment 6 Objectives
06.01.
Relate
for two points A and B within a continuous fluid
- pressure at point A
- fluid speed at point A
- fluid density at point A
- vertical position of point
A
-
pressure at point B
- fluid speed at point B
- fluid density at point B
- vertical position of point
B
- KE per unit volume at each point
- PE per unit volume at each point
- PE change of small mass from point A to point B
- KE change of small mass from point A to point B
- ratio of velocities if fluid is noncompressible
- ratio of cross-sectional areas if fluid is
noncompressible
|
Asst 06 |
Introductory Problem Set |
lab/activity |
text |
outline |
Class Notes |
other |
query |
|
06 |
Set 5, Probs 4-6 |
Kinetic Model Experiment [2] |
text_06 |
|
Class Notes
#06 |
|
query_6
|
|
Assignment 7 Objectives
07.01.
Relate
for a bottle-and-cap system with a vertical tube and a
pressure tube, between two states at constant temperature
- initial and final fluid level in vertical tube
- initial and final lengths of air column in pressure tube
- density of fluid
- volume ratio for air column in pressure tube
- excess pressure necessary to support excess fluid in
vertical tub
- atmospheric pressure
These objectives are met in the analysis of the lab
exercise for this assignment.
|
Asst 07 |
Introductory Problem Set |
lab/activity |
text |
outline |
Class Notes |
other |
query |
|
07 |
Set 5, Probs 7-9 |
Measuring Atmospheric Pressure, Part 1 [2] |
text_07 |
|
Class Notes
#07 |
|
query_7
|
|
Assignment 8
Objectives:
System 4:
08.01.
Determine the amount of thermal energy associated with a
given change in temperature for a confined gas,
Technically:
08.01
Relate
for a system consisting of n moles of a monotomic or diatomic
gas, where `dT is the temperature change, `dQ the thermal
energy required and C_p and C_v are the specific heats at
constant pressure and constant volume:
-
{n, R,
mon/diam,
C_p, C_v,
`dT, `dQ}
08.02. For a single particle of given mass moving at
given speed perpendicular to
and colliding elastically with a piston of given cross-sectional area,
with collisions occurring at a given regular time interval,
apply the impulse-momentum theorem to determine the average
force and average pressure exerted on the piston.
Technically:
08.02. For a single particle of mass m moving at speed v perpendicular to
and colliding elastically with a piston of cross-sectional area A_cs,
with time `dt between collisions, where p is the momentum, `dp the
change in momentum during a collision, F_ave the average force and
P_ave the average pressure on the piston:
-
Relate
{m, v, p, `dp, `dt,
F_ave}
-
Relate
{m, v, p, `dp, `dt,
F_ave, A_cs,
P_ave}
08.03. For a single particle of given mass moving at
given speed perpendicular to
and colliding elastically with the ends of a cylinder of given
length and cross-sectional area, apply the impulse-momentum
theorem to determine the average force and average pressure
exerted on the piston.
Technically:
08.03. For a single particle of mass m moving at speed v perpendicular to
and colliding elastically with the ends of a cylinder of
cross-sectional area A_cs and length L, with time `dt between
collisions, where p is the momentum, `dp the change in momentum
during a collision, F_ave the average force and P_ave the average
pressure on the piston:
-
Relate
{m, v, L, p,
dp, KE }
-
Relate
{m, v, L, `dt }
-
Relate
{m, v, L, p, `dp, `dt,
F_ave, KE,
A_cs,
P_ave}
08.04. For a given number of particles of equal given masses moving at
given speed perpendicular to
and colliding elastically with the ends of a cylinder of given
length and cross-sectional area, apply the impulse-momentum
theorem to determine the average force and average pressure
exerted on the piston, and relate the results to the
corresponding absolute temperature and total internal energy of
the system.
Technically:
08.04. For a large number N of particles each of mass m_particle moving at
speed v in a random direction in space, colliding elastically at an
end of a cylinder of cross-sectional area A_cs and length L, where
F_ave is the average force and P_ave the average pressure on the
end, KE_ave the average kinetic energy and v_Ave the (rms) average
velocity of the particles, n the number of moles, U the total
rotational and translational KE of the particles, T the absolute
temperature, n the number of moles, R the gas constant, k the
Boltzmann constant, N_A Avagodro's number and the gas monatomic or
diatomic:
-
Relate
{m_particle, N, v, L,
F_ave,
A_cs, P_ave}
-
Relate
{T,
m_particle,
KE_ave,
v_rms, N, n, U,
C_p, C_v,
monatomic/diatomic, R, k, N_A}
08.05. For a large given number of particles of equal
given masses moving at given speed, colliding randomly with one
another and elastically with the walls of a cylinder of given
length and cross-sectional area, apply the impulse-momentum
theorem to determine the average force and average pressure
exerted on the walls, and relate the results to the
corresponding absolute temperature and total internal energy of
the system, and to the volume of the system:
Technically:
08.05. Where in addition V is the volume, T_0, V_0, P_0, N_0 the initial
temperature, volume, pressure and number of particles, `dT the
change in absolute temperature, `dKE the change in KE, `dP the
change in pressure, `dN the change in the number of particles
-
Relate
{m, N, v, L,
Fave,
A_cs, P_ave,
KE_ave, V, T}
-
Relate
{direction of `dT, direction of `dKE,
direction of `dP, direction of `dV,
direction of `dN}
-
Relate
{`dT as percent of T_0, `dP
as percent of P_0, `dV as percent of
V_0, `dN as percent of N_0, `dT/T_0,
`dV/V_0, `dT/T_0,
`dN/N_0 | percent changes are small
}
08.06. For a thermodynamic system, where `dQ_in and `dQ_out
are the heat flowing into and out of the system during a cycle,
`dW the work done by the system, eff the efficiency of the
system, T_c and T_h the low and high temperatures between which
the system operates, eff_max the maximum possible efficiency
between these temperatures, eff_Carnot the efficiency of a
Carnot cycle operating between these temperatures,
-
Relate
{`dQ_in, `dQ_out, `dW, eff, T_0, T_f, eff_max, eff_Carnot}
08.07. For a 'bottle engine' consisting of n moles of
a confined monatomic or diatomic gas raising water to height
y_max as is operates between states 0, 1 and 2, where `dQ is the
heat input to the system during a cycles, `dPE the PE change of
the system, `dU the change in the internal energy of the system
and eff the ratio of PE change to input heat:
-
Relate
{P_0, V_0, T_0, n,
y_max, P_1, V_1,
T_1, T_f, P_2, V_2, T_2, `dQ,
`dPE, `dU,
eff, monatomic/diatomic}
08.08. For a confined monatomic or diatomic gas
expanding adiabatically or isothermally, where `dW is the work
done by the system, `dU the change in its internal energy and `dQ
the heat input:
-
Relate
{P_0, V_0,
T_0, P_f,
V_f,
T_f, adiabatic\isothermal, `dW,
`dU, `dQ,
monatomic/diatomic}
Objectives are covered in the text assignments, class
notes and Introductory Problem Sets.
|
Asst
#08 |
Introductory Problem Set |
lab/activity |
text |
outline |
Class Notes |
other |
query |
|
08 |
Set 5, Probs 16-20 |
Bottle Thermometer [2] |
text_08 |
|
Class Notes
#08,09 |
Calculus in Thermo |
query_8
|
|
No new objectives for Assignment 9. Review for test #1, which
is due after completing Assignments 0 - 9. |
Asst #09 |
Introductory Problem Set |
lab/activity |
text |
outline |
Class Notes |
other |
query |
|
09 |
|
PHeT 13.31 States of Matter 15.38 Reversible Reactions |
text_09 |
|
Class Notes
#10,11, 12 |
|
query_9 |
|
Module 2,
Assignments 10-22 |
Waves
·
Relationships among wave velocity, frequency, wavelength, density of
medium, tension of medium, amplitude, energy and period.
·
Superposition of waves
·
Nature of reflection at boundaries of various types and the
formation of standing waves between two points.
·
Determining wavelengths of the harmonics of a standing wave given
boundary conditions.
·
Determining frequencies of harmonics from wavelengths and
propagation velocity.
·
Energy in standing and traveling waves
|
|
Waves and Optics:
-
v = f * `lambda:
The
frequency f
tells us how many peak-to-peak cycles of a traveling wave past
in a unit of time. The
wavelength `lambda
tells us the distance between consecutive peaks of the wave.
Thus when we multiply the frequency by the wavelength we obtain
the distance travel by the disturbance in a unit of time, which
is the velocity at which the disturbance propagates.
T = 1 / f:
The
period T
is the time required for a peak-to-peak cycle, and is equal to the
reciprocal of the frequency:
T = 1 / f.
`omega = 2 `pi f:
The
angular frequency `omega
is the velocity of the point moving around the reference circle
which models the simple harmonic motion of a single point as the
wave passes. Since there are 2 `pi radians in a circle,
`omega = 2 `pi f.
-
y = A sin( (2 `pi f) (t - x / v) ):
If the disturbance at the left-hand end of a wave traveling to
the right has the form y = A sin ( (2 `pi f) t), then if the
wave has propagation velocity v the disturbance will require a
time delay `dt = x / v
to reach position x. It follows that the disturbance at position
x will satisfy the equation
y = A sin( (2 `pi f) (t - x / v) ).
-
v = `sqrt ( T
/ `mu ):
In a uniform string whose mass per unit length is
`mu = m / L,
under uniform tension T, application of the impulse-momentum
theorem shows that a transverse disturbance will travel at
velocity
v = `sqrt( T / `mu ).
v = `sqrt(
B / `rho):
In a
liquid medium
the velocity with which a disturbance is propagated is given by
v = `sqrt( B / `rho),
where
B is the bulk modulus
and
`rho the density
of the liquid.
v = `sqrt( Y
/ `rho):
In a
solid medium
the velocity with which a disturbance is propagated is given by
v = `sqrt( Y / `rho),
where
Y is the Young's modulus
and
`rho the density
of the solid.
v = `sqrt(
`gamma * p / `rho):
In an ideal gas we have
propagation velocity v = `sqrt( `gamma p
/ `rho),
where
`gamma is the ratio Cp / Cv
of specific heat at constant pressure to specific heat at constant
volume,
p is the pressure
of the gas and
`rho
its
density.
Since for an ideal gas p / `rho = RT / M, where R is the gas
constant, T the temperature and M the molar mass, we can also write
v = `sqrt( `gamma * R T / M).
-
`lambda = L * (2 / n), n = 1, 2, 3, ...:
For a
standing wave in a linear medium,
where the wave is constrained to have
nodes separated by distance L,
then the
number of node-antinode distances
spanning distance L is a
multiple of 2.
Since
4 node-antinode distances
are required to
span a wavelength,
the
possible wavelengths
are
2 L
(corresponding to 2 node-antinode
spans in distance L),
L
(corresponding to 4 node-antinode
spans in distance L),
2/3 * L
(corresponding to 6 node-antinode
spans in distance L),
1/2 * L
(corresponding to 8 node-antinode
spans in distance L), etc..
The
corresponding frequencies
are the
f = v / `lambda
values
v / ( 2 L), v / (L), v / (2/3 * L), etc.,
making up the series 1/2 * v / L, 1 * v / L, 3/2 * v / L, 4 * v / L,
summarized by the formula
f = (n / 2) * v / L.
The
same results
apply for much the same reasons when
antinodes occur with separation L.
-
`lambda = L * (4 / (2n - 1) ), n = 1, 2, 3, ...
For a
standing wave
in a linear medium, where the wave is constrained to have
nodes separated from antinodes by distance L,
then the
number of node-antinode distances
spanning distance L is 1 plus a multiple of 2--i.e.,
an odd number.
Since 4 node-antinode distances are
required to span a wavelength, the
possible wavelengths
are
4 L
(corresponding to 1 node-antinode
spans in distance L),
4/3 L
(corresponding to 3 node-antinode
spans in distance L),
4/5 * L
(corresponding to 5 node-antinode
spans in distance L),
4/7 * L
(corresponding to 7 node-antinode
spans in distance L), etc..
The
corresponding frequencies
are the f = v / `lambda values v / ( 4
L), v / (4/3 * L), v / (4/5 * L), etc., making up the series 1/4 * v
/ L, 3/4 * v / L, 5/4 * v / L, 7/4 * v / L, summarized by the
formula
f = (2n-1)/4 * v / L.
-
f
' = f / (1 - vSource/vSound).
When a
source
of sound emitting pulses with frequency f is
moving toward an observer
with velocity vSource then if the
speed of sound is vSound, the
frequency detected by the observer is f ' = f / (1 -
vSource/vSound).
This is an instance of the
Doppler Effect.
-
f
' = f (1 + vObserver /
vSound ):
If an observer
is moving toward a source
which is emitting a sound with frequency f, then if the speed of
sound is vSound the frequency
detected by the observer will be f ' = f (1 +
vObserver /
vSound ). This is another instance of the
Doppler Effect.
-
path
difference = a sin(`theta).
If waves are emitted in phase from two points separated by
distance a, then if the waves are detected at a distance much
greater than a, and at a position P such that a line from either
source to P makes an angle `theta with the perpendicular
bisector of the line segment connecting the sources, the
distances traveled
by the two waves will
differ by distance a sin(`theta).
If this
path difference
is equal to
half of a wavelength
the two waves will arrive at P
exactly out of phase
and the net disturbance at P will be 0. We call this
destructive interference.
If the
path difference
is equal to a
whole wavelength
or to any
multiple of a whole wavelength
the two waves will arrive at P
exactly in phase
and the net disturbance will be double that of either of the
individual disturbances. We call this
constructive interference.
The condition for constructive interference is that
path difference = n * `lambda for n = 0, 1, 2,
....
If the
path difference
is equal to a
whole wavelength plus a half wavelength
we will again have
destructive interference.
The condition for destructive interference is that
path difference = (n + 1/2) * `lambda for n = 0, 1, 2,
... .
-
sin(`theta1) / sin(`theta2) = n2 / n1:
Snell's Law states that if
`theta1
and
`theta2
are the
angles of incidence and refraction
for a beam of electromagnetic radiation which is directed from
one material into another, then the sines
of those angles are inversely proportional to the
indices of refraction n1 and n2
of the two materials. The
index of refraction
for a material is the
number n
such that
v = c / n,
where v is the propagation velocity of the electromagnetic
radiation in the material and c the propagation velocity of
electromagnetic radiation in a vacuum. For most materials n
varies with the wavelength of the electromagnetic radiation,
which leads to the phenomenon known as
dispersion.
-
Critical Angle (angle of total internal reflection):
Total internal reflection
occurs whenever the
angle of incidence
is
greater than
that for which the
angle of refraction is 90 degrees.
If `theta1 and `theta2 are the angles of incidence and
refraction and n1 and n2 the corresponding indices of
refraction, then sin(`theta2) = n2 /
n1 * sin(`theta1) and
if sin(`theta1) = n1 / n2, then sin(`theta2) = 1 and the angle
of refraction will be 90 degrees.
The value of `theta1 for which sin(`theta1)
= n1 / n2 is called the
critical angle.
For any angle of incidence
greater that the critical angle
we will have
total internal reflection.
|
|
Assignment #10 Objectives:
10.01.
Solve problems and analyze real-world situations involving the
wavelength, frequency, angular frequency, and mathematical
representation of a traveling wave.
Technically:
Relate
for a traveling sine wave
- lambda (wavelength)
- f (frequency)
- omega (angular frequency)
- T (period)
- A (amplitude)
- 'time delay' between two
points
- equation of motion of point
at end
- equation of motion of
arbitrary point
- waveform at given instant t
10.02. Calculate the
beat frequency of a system driven by oscillations of two
independent oscillators, and explain the origin of the beats.
Technically:
Relate
for an oscillation driven by two independent oscillators
- f_1 (frequency of first
oscillator)
- f_2 (frequency of second
oscillator)
- f_beat (beat frequency)
- n (number of beats occurring
during time interval `dt)
- `dt (time interval)
10.03. Given any of the three
quantities pulse velocity, string mass, string length, string
tension calculate the fourth, as well as the frequency of the
first harmonic.
Technically:
Relate
for a string:
- pulse velocity c
- string mass m
- string length L
- string tension T
- frequency of first harmonic
Information to fulfill the Objectives is contained in the
Introset assignment and Class Notes.
|
Asst #10 |
Introductory Problem Set |
lab/activity |
text |
outline |
Class Notes |
other |
query |
|
10 |
Set 6, Probs 1-10 (phy
122 only 1-8) |
Experiments to View |
text_10 |
System 7:
-
2 independent pendulums: {f_1, f_2, n,
f_beat}
|
Class Notes
#12 |
Practice Test |
query_10
wavelength, freq, etc; per wave mth; all
introset |
|
Assignment #11 Objectives
11.01.
Analyze the characteristics of standing waves, including
frequency, wavelength, amplitude, propagation velocity and
waveforms.
Technically:
Relate
for longitudinal or transverse standing waves in a given object of
given length
- boundary conditions
- positions of nodes and
antinodes for fundamental oscillation
- lambda_1 (wavelength of
fundamental oscillation)
- positions of nodes and
antinodes for first n harmonics (n <= 4)
- pattern of positions of
nodes and antinodes for subsequent harmonics
- positions of nodes and
antinodes for nth harmonic
- lambda_n (wavelength of nth
harmonic)
- c (propagation velocity)
- f_n (frequency of nth
harmonic)
- A_max (amplitude of oscillation at antinode)
- A(x) (amplitude at position
x)
- y(x, t) (position relative
to equilibrium of point at position x along the object, at clock
time t)
- sketch of y(x) for given t
- graph of y(t) for given x
|
Asst #11 |
Introductory Problem Set |
lab/activity |
text |
outline |
Class Notes |
other |
query |
|
11 |
Set 6, Probs 11-13 |
Measuring Atmospheric Pressure, Part 2
[2]
Experiments to View |
text_11 |
|
Class Notes
#13 |
|
query_11
harmonics
univ
eqn of wave |
|
Assignment #12 Objectives
12.02.
Apply the relationships among tension, mass, length and
propagation velocity to solve problems relating to waves on a
string.
Technically:
Relate
for a traverse standing wave in string or chain under uniform tension
- T (tension)
- c (propagation velocity)
- m (total mass)
- L (length)
12.03.
Apply the principle of superposition to analyze waveforms of
traveling waves and write their mathematical representations.
Technically,
Relate
the following:
- waveform y_1(x), given
mathematically or graphically
- waveform y_2(x), given
mathematically or graphically
- superposed waveform y_1(x) +
y_2(x), constructed graphically
- superposed waveform y_1(x) +
y_2(x), represented mathematically
- equation y_1(t, x) of
traveling or harmonic wave
- equation y_2(t, x) of
traveling or harmonic wave
- equation of superposed wave
12.04.
Apply the principle
of superposition to analyze waveforms of standing harmonic waves
and write their mathematical representations
Technically,
Relate
the following:
- traveling sine wave y_1(t,
x) traveling in positive direction, traveling sine wave y_2(t,
x) traveling in opposite direction, both with common propagation
speed c, frequency f and amplitude A
- evolution of waveform of
superposed wave between two specified points
- boundary conditions
- number of harmonic
- matching selection of points
- evolution of cycle of given
harmonic
12.05.
Relate
- traveling wave incident on
fixed or free boundary
- reflected wave
Objectives are to be achieved by continuing to work on
previously assigned tasks.
|
Asst #12 |
Introductory Problem Set |
lab/activity |
text |
outline |
Class Notes |
other |
query |
|
12 |
Set 6, Problems 1-8 |
|
text_12 |
|
|
|
query_12
|
|
Assignment #13 Objectives
13.01.
Calculate energy and power for a wave.
Technically:
Relate
for a wave traveling through a medium
- amplitude
- frequency
- mass per unit length
- energy per unit length
- propagation velocity
- power
For example fine the power
given the amplitude, frequency, velocity of propagation and mass
per unit length.
Objectives are addressed in
the Introset, text and Class Notes.
|
Asst #13 |
Introductory Problem Set |
lab/activity |
text |
outline |
Class Notes |
other |
query |
|
13 |
Set 6, Probs 11-16 |
Initial Activities with Waves and Optics. [2] |
text_13 |
|
Class Notes
#14 |
|
query_13
harmonics, energy in wave etc.x |
|
Assignment #14 Objectives
14.01.
Analyze the Doppler Effect for sources and/or observers moving
relative to the medium.
Technically:
Relate
for a wave created by a source moving with velocity v_s and
observed by an observer moving with velocity v_o through a
medium in which propagation velocity of the wave is c
Objectives are addressed in the Introset assignment and in
the Class Notes.
|
Asst #14 |
Introductory Problem Set |
lab/activity |
text |
outline |
Class Notes |
other |
query |
|
14 |
Set 6, Probs 17-21 |
PHeT
16.34 Waves on a String |
text_14 |
|
Class Notes
#15 |
|
query_14
|
|
Assignment #15 Objectives
15.01.
Analyze the implications of resonant frequencies in an aluminum
rod.
Technically:
Relate
for an aluminum rod which is supported at its middle and free at
both ends
- length
- frequency of fundamental
harmonic of longitudinal wave
- wavelength
- propagation velocity of
sound in aluminum
- small change in position of
support
- change in beat frequency as
proportion of original beat frequency
15.02.
Calculate energy, power and intensity of sound waves.
Relate
for a sound wave
- pressure amplitude
- intensity
- area
- power of source
- threshold intensity
- decibel level
Objectives are addressed in
the text and lab assignments.
|
Asst #15 |
Introductory Problem Set |
lab/activity |
text |
outline |
Class Notes |
other |
query |
|
15 |
Set 6, Problems 17-21 |
Experiments to View |
text_15 |
|
Class Notes
#16 |
|
query_15
|
|
Assignment #16 Objectives |
Asst #16 |
Introductory Problem Set |
lab/activity |
text |
outline |
Class Notes |
other |
query |
|
16 |
Set 6, Problems 9-10 |
PHeT
16.43 Wave Interference, 17.34 Sound |
text_16 |
|
|
|
query_16
|
|
Objectives:
17.01. Analyze straight
lines representing rays of light refracted by lenses and
mirrors.
Relate
for two broken-line paths, each defined by three points in the
coordinate plane, and apply to image formation by thin lenses.
- coordinates of the three
defining points for each path
- x and y intercepts of the
paths
- point(s) of intersection of
the paths
- triangles formed by paths
with one another and with the coordinate axes
- sets of similar triangles
and relative dimensions
17.02. Calculate the
relatationships among image and object distances, focal lengths,
magnifications for thin lenses.
Relate
for a thin converging or diverging lens
- image distance
- object distance
- focal distance
- magnification
- nature of image
- diagrams of principle rays
17.03. Calculate the
path difference from two given points to a third given point.
Relate
for a given point (x_0, 0) on the x axis of the coordinate plane,
two points (0, y_1) and (0, y_2) on the y axis and a wavelength
- length of path 1 from (x_0,
0) to (0, y_1)
- length of path 2 from (x_0,
0) to (0, y_2)
- difference in path lengths
- difference in path lengths
as a multiple of wavelength
17.04. For points (0, -a/2) and (0, a/2)
on the coordinate plane and a wavelength lambda < a
- using a sketch depict
the path difference corresponding to a distant observer, along
paths making angle theta with the x axis
- calculate the path
difference
- calculate the path
difference as a multiple of lambda
- determine angles for which
the path difference is an integer multiple of lambda
- determine angles for which
the path difference is an integer multiple of lambda plus a
half-wavelength
- apply to situations
involving the two-slit phenomenon
17.05. Analyze straight
lines representing rays of light refracted by lenses and
mirrors.
Relate
for two broken-line paths, each defined by three points in the
coordinate plane, and apply to image formation by thin lenses.
- coordinates of the three
defining points for each path
- x and y intercepts of the
paths
- point(s) of intersection of
the paths
- triangles formed by paths
with one another and with the coordinate axes
- sets of similar triangles
and relative dimensions
17.06. Calculate the
relatationships among image and object distances, focal lengths,
magnifications for thin lenses.
Relate
for a thin converging or diverging lens
- image distance
- object distance
- focal distance
- magnification
- nature of image
- diagrams of principle rays
17.07. Calculate the
path difference from two given points to a third given point.
Relate
for a given point (x_0, 0) on the x axis of the coordinate plane,
two points (0, y_1) and (0, y_2) on the y axis and a wavelength
- length of path 1 from (x_0,
0) to (0, y_1)
- length of path 2 from (x_0,
0) to (0, y_2)
- difference in path lengths
- difference in path lengths
as a multiple of wavelength
17.08. For points (0, -a/2) and (0, a/2)
on the coordinate plane and a wavelength lambda < a
- using a sketch depict
the path difference corresponding to a distant observer, along
paths making angle theta with the x axis
- calculate the path
difference
- calculate the path
difference as a multiple of lambda
- determine angles for which
the path difference is an integer multiple of lambda
- determine angles for which
the path difference is an integer multiple of lambda plus a
half-wavelength
- apply to situations
involving the two-slit phenomenon
17.09. Calculate image
formation by a combination of two lenses.
Relate
for two lenses
- focal lengths
- position of object with
respect to first lens
- position of image formed by
first lens
- position of second lens
- position of image formed by
second lens
- characteristics of each
image
17.10. Calculate the
characterstics of refraction.
Relate
for a plane wave incident from one medium at a plane interface with
a second:
- indices of refraction
- angle of incidence
- angle of refraction
- speed of light in each
medium
Objectives are addressed
in Introductory Problem Sets, the text and the Class Notes.
|
Asst #17 |
Introductory Problem Set |
lab/activity |
text |
outline |
Class Notes |
other |
query |
|
17 |
Set 6, Probs 22-24 |
Experiments to View |
text_17 |
|
Class Notes
#17, 18 |
|
query_17
|
|
Assignment #18 Objectives
18.01. Sketch and analyze the path of
light incident on an reflected or refracted by a thin lens, a mirror
or a prism.
|
Asst #18 |
Introductory Problem Set |
lab/activity |
text |
outline |
Class Notes |
other |
query |
|
18 |
|
Resolving Images
[2]
Experiment 26: Circular Lens and Circular Mirror (do
the experiment but don't write it up--just respond to the query
program). Note the summary document
Index of Refraction from Focal Point of Liquid-Filled Cylinder
[2]
|
text_18 |
|
Class Notes
|
|
query_18
|
|
Assignment #19 Objectives
19.01 Sketch and analyze the path of
light incident on a thick cylindrical interface.
|
Asst #19 |
Introductory Problem Set |
lab/activity |
text |
outline |
Class Notes |
other |
query |
|
19 |
|
focusing_light_thru_cylindrical_lens [2] |
text_19 |
|
Class Notes
#20 |
|
query_19
|
|
Assignment #20 Objectives
20.01. Analyze image formation by a
combination of thin lenses.
20.02. Analyze interference patterns for thin films, single
slits, double slits and diffraction gratings.
|
Asst #20 |
Introductory Problem Set |
lab/activity |
text |
outline |
Class Notes |
other |
query |
|
20 |
|
Image Formation; Combining Lenses [2]
PHeT
25.26 Geometric Optics |
text_20 |
|
|
|
query_20
|
|
Assignment #21 Objectives
21.01. Explain how radio waves could be
polarized when passing through a series of vertical or horizontal
metal posts, and whether the resulting waves would be polarized
vertically or horizontally.
21.02. Calculate Brewster's angle for light incident from a
medium with index of refraction n_1 on a smooth flat surface with
index of refraction n_2.
|
Asst #21 |
Introductory Problem Set |
lab/activity |
text |
outline |
Class Notes |
other |
query |
|
21 |
|
Interference [2] |
text_21 |
|
Class Notes
#21 |
|
query_21
|
|
Assignment #22 Objectives There are no new objectives for Assignment
22. Review for Test #2 and take the test after completing
Assignments 19-22. |
Asst #22 |
Introductory Problem Set |
lab/activity |
text |
outline |
Class Notes |
other |
query |
|
22 |
|
|
text_22 |
|
|
Partial Summary of Intro Problem Set |
query_22
|
|
Module 3, Assignments 23 -
33 |
Electrostatics
·
Coulomb’s Law, electric fields, superposition of fields.
·
Gaussian surfaces
·
Energy, potential difference, potential functions.
Electrical Circuits
·
Ohm’s Law, Series and Parallel Circuits,
Kirchoff’s Laws, Energy Relationships
Magnetism
·
Magnetic fields.
·
Interaction between magnetic fields and moving electric charges.
·
Magnetic fields as the result of moving charges.
·
Magnetic flux, EMF resulting from changing magnetic flux.
|
|
-
Coulomb's Law and its Consequences:
F = k * q1 * q2 / r^2,
where k = 9 * 10^9 N m^2 / C^2, q1 and q2 are
two point charges,
r is the
distance separating the charges
and F is the
force between the two charges.
The force F is exerted on each charge by the other. If q1 and q2
are of
like sign
the force will be one of
attraction along the line
between the two charges; otherwise the force will be one of
repulsion
in the direction of the line defined by the two charges. This law is
known as
Coulomb's Law.
-
E = k q / r^2:
The
electric field E
at a point P, due to a point charge q at another point Q, is the
force
experienced
per Coulomb of test charge
when the test charge is introduced
at the point P.
This field is directed
along the line
defined by P and Q, and is directed
away from P
if q is
positive
and
toward P
is q is
negative.
-
F = q * E:
The
force
exerted
on a charge q
in
electric field E
is equal to the
product q * E.
If
q is positive
the force will be exerted
in the direction
of the
field;
if q is
negative
the force will be exerted in the
direction opposite
that of the field.
-
Electrostatic Flux = 4 `pi k Q:
The
total electrostatic flux
through a
closed surface
is 4 `pi k Q, where
Q is the total charge
enclosed by the surface.
E = k Q / r^2:
If the charge distribution is
spherically symmetric,
then the
electric field
due to that distribution will be
spherically symmetric about the same central point.
The
field
will be directed
radially
outward
from the
center
and will hence be
perpendicular
to the surface of any
concentric sphere.
Thus for any such sphere we have uniform electric field E = 4 `pi k
Q / ( 4 `pi r^2) = k Q / r^2, where Q is
the total charge enclosed by the sphere. Note that this agrees with
Coulomb's Law in the case of a point charge q.
E = 2 k `lambda / r:
If a charge distribution is
cylindrically symmetric,
then the
electric field
due to that distribution will be
cylindrically symmetric about the central axis
of the distribution. The
field
will be directed
radially
outward
from the
central axis
and will hence be
perpendicular
to the
curved surface
of any coaxial
cylinder.
Thus if
`lambda
is the amount of
charge per unit length
enclosed by the cylinder, a
cylinder
of radius r and length L will
enclose charge Q
=
`lambda
* L. Since the
curved surface
of the cylinder will have
area A = 2 `pi r * L,
the
field
at the
surface of the cylinder
will be E = 4 `pi k Q / r^2 = 4 `pi k ( `lambda
* L) / (2 `pi r * L) = 2 k `lambda / r.
E = 2 `pi k `sigma:
If charge is
uniformly distributed
over a
large plane area,
then
symmetry arguments
show that
near that plane
but
not close to its edges
the electric field due to the distribution is
very nearly perpendicular
to the plane. It follows that if the
charge per unit area
is
`sigma,
then a
rectangular box
with its central axis oriented
perpendicular to the plane,
with the box intersecting the plane and having
cross-sectional area A
perpendicular to the plane, will contain
charge Q = `sigma * A.
The
electrostatic flux
will
exit
this box
through its two ends
and not through its sides, so the flux will be E *
( 2 A). We therefore have E
( 2 A) = 4 `pi k ( `sigma * A) and E = 4
`pi k ( `sigma * A ) / ( 2 A) = 2 `pi k `sigma. Note that as long as
we remain near the plane, in the sense already specified, the
electric field remains constant.
Work, Energy, Potential Difference, Power:
-
`dW(ON)
= q * E * `ds:
The
work done ON a charge q
which moves through a
displacement `ds in the direction
of a
uniform electric field E
is `dW = F * `ds
= (q * E) * `ds. The work done BY
the charge against the field is the negative of this quantity.
-
V = E * `ds.
The
potential difference V
between two points is the
work
required
per unit charge
to move charge from the
first point
to the
second.
In a
uniform electric field E
the work to move a
charge q
through
displacement `ds
in the
direction of the field
is `dW(ON)
= q * E * `ds, so the
potential difference
is V = `dW(ON) / q = q * E * `ds
/ q = E * `ds. The
unit
of this
potential difference
is the
Joule / Coulomb,
which is the
Volt.
-
F = q * `dV / `ds.
If
`dV
is the
potential difference
corresponding to a
displacement `ds
in the direction of a
constant electric field,
then the
potential gradient
of the field is
`dV / `ds.
In this case the force on a charge q is the product of the
charge and the potential gradient.
-
`dKE = -`dW(BY).
The
change in the kinetic energy
of a charge particle, in the absence of dissipative forces, is
equal and opposite
to
the
work
done
by the particle
against an electrostatic field.
Electrostatic fields are conservative,
and the
forces
on charged subatomic particles within such fields usually exceed
any dissipative forces to the extent that the
dissipative forces are negligible.
In this case energy conservation tells us that the
kinetic energy change
of such a particle will be equal to the
work done on the system
by the electrostatic field, or to the
negative
of the work done
by the system
against the electrostatic field.
-
P = I * V:
The
power
required to move charge at the
rate I
(standard unit Coulombs / sec or amps) through a
potential difference V
(standard unit Joules / Coulomb or volts) is the
product I * V
of the rate and potential difference (when we multiplied
Coulombs/second by Joules/Coulomb we get Joules/second, or
watts).
Conduction by Charge Carriers:
-
(Rate of charge passage = N / L * vDrift).
If there are
N charge carriers
uniformly distributed over a
length L,
then the number of
charge carriers per unit length
is
N / L.
If those charge carriers, which typically have small mass and
which therefore have large thermal velocity, have an
average net drift velocity
vDrift
along the length, then the
number of charges
passing a
given point
per
unit of time
is given by
N / L * vDrift.
-
Rate of charge passage = charge density * A *
vDrift.
The number of
charges per unit
of
length
in a
uniform conducting wire
depends on the
volume density
of
charge carriers
in the wire and on the
cross-sectional area A
of the wire. We have
N / L = charge density * A,
so that the
number
of charges passing a
given point
per unit of
time
is
charge density * A * vDrift.
-
The
average drift velocity
of the charge carriers in a substance is
proportional
to the strength of the
electric field,
which is
equal
to the
potential gradient.
For a uniform conducting wire with
potential difference `dV
between its ends, the strength of this
electric field
or
potential gradient
is
`dV / L.
-
(Rate of Charge Passage proportional to A * `dV
/ L).
The
drift velocity
is affected by
various factors
that vary with temperature and from one substance to another.
For
given substance
at a
given temperature
the
drift velocity
is
proportional
to
`dV / L,
so that the
number of charges
passing a given point per
unit time
is
proportional
to
charge density * A * `dV / L.
Since
charge density
also
depends
on the
substance
and temperature, we can say that the
number of charges
passing a given point
per unit
of time for a given substance and temperature is
proportional
to
A * `dV / L.
-
(`dV / R proportional to A * `dV
/ L).
The
number of charges
passing a given point per
unit of time
is the
current,
designated I. Thus for given substance at a given temperature
I is proportional to A * `dV / L.
Ohm's Law
tells us that
I = `dV / R,
where R is the
resistance
of the conductor to the flow of current (see below; for the
present model `dV is the voltage V
across the conductor). Thus
`dV / R
is
proportional
to
A * `dV / L,
so
1 / R
is
proportional
to
A / L
and
R
is
proportional
to
L / A.
-
R = `rho * L / A.
We call the
proportionality constant
between R and L / A the
resistivity
of the substance, and we use the symbol
`rho
for the resistivity. Thus
R = `rho * L / A.
The
resistance
to the flow of current is
proportional
to the
length
of the conductor (greater L implies lower potential gradient, or
electrical field strength, `dV / L,
which results in lower drift velocity and therefore lower
current) and
inversely proportional
to its
cross-sectional area
(greater A implies more charge carriers and hence more current
flow for a give drift velocity).
Ohm's Law and Circuits:
-
I = V / R.
Ohm's Law expresses the fact that the
current I
in a conductor is
proportional to the voltage
across the conductor and
inversely proportional
to the quantity called
resistance.
Using V for the voltage and R for the resistance this is
expressed as I = V / R.
-
P = V^2 / R.
If a
voltage V
is applied across a
resistance R
the
resulting current
is
I = V / R.
A
current I
passing through a
potential difference V
requires
power P = I * V
so P = (V / R) * V = V^2 / R.
-
R = R1 + R2, series resistances.
If a
current I
passes
through two
resistances R1 and R2 without branching,
we say that the two
resistances are in series.
In this case voltages
V1 = I * R1
and
V2 = I * R2
are required across the resistances. Since the resistances,
hence the voltages, are in series the
total voltage
across the combination is
V1 + V2 = I * R1 + I * R2,
or V = I * (R1 + R2). Thus
I = V / ( R1 + R2)
and we can say that the
resistance of the series combination
is R1 + R2.
-
1 / R = 1 / R1 + 1 / R2, parallel resistances:
If a
voltage V
is maintained across a
parallel combination
of two resistances
R1 and R2,
then the
entire voltage
is experienced by
both resistances.
Hence current
I1 = V / R1
flows through the
first resistance
and
I2 = V / R2
flows through the
second,
giving a
total current
I = I1 + I 2 = V / R1 + V / R2. So I = V ( 1
/ R1 + 1 / R2). Since I = V / R, we have 1 / R = 1 / R1 + 1 /
R2.
Capacitors and Capacitance:
-
C = Q / V.
A
capacitor,
when a potential difference is maintained between its terminals,
stores charge in proportion
to that
potential difference.
Capacitance
is defined as C = stored charge / voltage = Q / V.
-
C = A / (4 `pi k Q)
(parallel-plate capacitor). A
parallel-plate capacitor
consists of two
flat plates
each with
area A,
with a
uniform separation d.
If
charge Q
is taken
from one
initially uncharged
plate
and placed
on the other,
then the plates will have charges Q and -Q and
charge densities
Q / A and -Q / A. The resulting
electric fields
will therefore be
E1 = 2 `pi k Q / A,
directed
away
from the
first plate,
and
E2 = 2 `pi k Q / A
directed
toward
the
second plate.
Provided
d is small
compared to the dimensions of the plates,
between the plates
the
field
will therefore be
4 `pi k Q / A,
directed
from
the
first plate
toward the
second,
and
outside
the plates
field
will be
zero.
The
voltage
between the plates will be
V = E * d
= 4 `pi k Q / A * d, and the
capacitance,
defined as Q / V, will be
C = Q / (4 `pi k Q / A * d) = A / (4 `pi k * d).
-
C = C1 + C2
(capacitors in parallel). A
parallel combination
of two capacitors with capacitance C1 and C2 will maintain the
same potential difference
across both. The
total charge
is therefore the
sum
of the two charges that would result from that potential
difference, and as a result
capacitance
is the
sum
of the
two capacitances.
-
1/C = 1/C1 + 1/C1
(capacitors in series). A
series combination
of two capacitors with capacitance C1 and C2 will result in
equal charges
Q on both capacitors. This results in
series voltages
V1 = Q / C1 and V2 = Q / C2 so that
total voltage
is
V = Q ( 1 / C1 + 1 / C2)
and we have
V / Q = 1 / C1 + 1 / C2.
Since the
capacitance
of the
combination
is
C = Q / V,
we see than 1 / C = 1 / C1 + 1 / C2.
Magnetism:
-
B = k ' I * `dL / r^2:
Magnetic fields are caused by electrical currents. A
current I
flowing thru a
short straight segment `dL
(think for example of a short segment of a straight conductor)
will contribute
k ' I `dL / r^2
to the
magnetic field B
at a point P, lying at distance r, provided that a
line
from the
segment
to
P
is
perpendicular to the segment.
k ' = 10^-7 Tesla / (amp meter). The
direction
of the field contribution at P is
perpendicular
to both
`dL
and to the
line
from the segment to P, according to the
right-hand rule.
-
B = k ' I * `dL / r^2 * sin(`theta):
A
current I
flowing thru a short straight
segment `dL
will contribute
k ' I `dL / r^2 sin(`theta)
to the
magnetic field B
at a
point P,
lying at distance r, if the
line
from the segment to P makes
angle `theta
with the segment. If `theta is a right angle then this rule is
identical to the rule of the preceding paragraph.
k ' = 10^-7 Tesla / (amp meter). The
direction
of the field contribution at P is
perpendicular
to both
`dL
and to the
line
from the
segment
to
P,
according to the
right-hand rule.
-
B = 2 k ' * `pi I / a
(field at the center of a single circular loop of radius a). If
we add up
all the k ' I `dL / r^2
contributions
from a
single loop
of wire of
radius a,
adding to obtain the
field
at the
center of the loop,
we find that if the loop is in a
horizontal plane
and the current goes around the loop in the
counterclockwise
direction the
magnetic field
contributed by
each segment
is directed
vertically upward.
Thus
all
the individual k ' I `dL / r^2
contributions
are in the
same direction
and their magnitudes
add
to the
total magnitude
of the
magnetic field.
Since the
total `dL
is equal to the
circumference
2 `pi a of the loop and
r = a
we can replace `dL by 2 `pi a and r
by a to get B = k ' I ( 2 `pi a ) /
a^2 = 2 k ' * I / a.
-
`phi = F * A *
cos(`theta):
The
flux,
designated
`phi,
of any
constant field F
which penetrate a
planar surface
whose
area
is
A
is equal to the
product
of the
component
of F
perpendicular to the surface,
and the
area
of the
surface.
Here
`theta
is the
angle
of the field F with a
line perpendicular
to the surface. The
component
of F
perpendicular
to the surface is therefore
F * cos(`theta),
and the flux is the
product
of this
perpendicular component
and the
area:
flux = F * cos(`theta) * A = F * A *
cos(`theta).
-
Vave
= `d`phi / `dt
(ave voltage =
ave rate of change of electrostatic flux): When the
electrostatic flux
`phi = E * A cos(`theta)
due to an
electrostatic field E
through a
loop of area A
is
changed
by amount
`d`phi
in a
time interval
of
duration `dt,
a
potential difference
with
average value
Vave
= `d`phi / `dt
is created around the loop.
-
| Vave | = 4 * A * E * f
(ave magnitude of a voltage produced
when a loop of area A is rotated at frequency f in the presence
of an electric field E): When a
loop
of
area A
is rotated with
frequency f
about an
axis perpendicular
to a
constant electric field E,
then the
time required
for the loop to rotate from
perpendicular
to
parallel
with the field is
1/4
of the
period of rotation.
The
period of rotation
is the reciprocal
T = 1 / f
of the frequency. So in
`dt
= 1/ 4 T = 1
/ (4 f )
we have a
change in flux
from `phi = A * E to `phi = 0, a change of magnitude
| `d `phi | = A * E.
This implies
average voltage
vAve
= `d`phi / `dt
= A * E / (1 / (4 f) ) = 4 * A * E *
f.
-
F = q v B
(force on a moving charge in the presence of the magnetic field,
velocity and field perpendicular): When a
charge q
moves with
velocity v perpendicular
to a
magnetic field B,
it experiences a force
F = q v B
directed
perpendicular
to both the
velocity
v and the
magnetic field
B, with the direction determined by the
right-hand rule.
-
m v^2 / r = q v B
(force on a moving charge in the presence of a perpendicular
magnetic field is equal to the centripetal force on the charge):
When a
charge q
moves with
velocity v perpendicular
to a
uniform magnetic field B,
the
force
being
perpendicular
to the
velocity
constitutes a
centripetal force m v^2 / r.
The particle will move in a
circular orbit
of
radius r,
where r is the
solution
to the
equation
m v^2 / r = q v B.
-
v = | E / B |
(velocity of a charge to particle moving in a straight line
through 'crossed' electric and magnetic field): When a particle
with charge q passes through
uniform electric
and
magnetic fields
which make
right angles
with one another, and the
velocity
of the particle is
perpendicular
to
both
of these
fields,
then
if the particle travels in a straight line
this means that
net force
on the particle is
zero.
This can only happen if the
electrostatic force
q E is
equal
and
opposite
to the
magnetic force
q v B, so that
| q E | = | q v B |.
Solving for v, the magnitude of the velocity, we easily obtain v
= | E / B |.
-
F = I L B sin(`theta)
(force on a straight current segment in the presence of a
uniform magnetic field): When a
current I
flows in a
straight conductor
of
length L,
in the presence of a
magnetic field B
making
angle `theta
with the conductor, then the field exerts a
total force
F = I L B sin(`theta), with the
direction
of the force
perpendicular
to both
B
and
I,
the direction determined by the
right-hand rule.
|
|
Assignment #23- 24 Objectives
23.01. Use Coulomb's
Law to determine the magnitudes of forces between charges in the
coordinate plane.
Technically:
Relate
each of the following sets:
{q1, q2, k, epsilon_0,
F, r}
{q1, q2, k, epsilon_0, F, PE}
where q_1 and q_2 are
charges, (x_1, y_1) and (x_2, y_2) their positions in the plane, r
the distance between them, F the magnitude of the force of their
interaction, k = 1 / (4 pi epsilon_0) = 9 * 10^9 N m^2 / C^2, epsilon_0 the permittivity of
free space, PE the electrostatic potential energy of the two-charge
system relative to infinite separation (PE
incorporated in asst 25).
23.02.
Use Coulomb's Law to determine
the vector forces between charges in the coordinate plane.
Technically:
Relate
{q1, q2, k, epsilon_0,
r, F_12, F_21, PE}
where r is the
vector from charge 1 to charge 2, F_12 the vector force
exerted on charge 1 by charge 2,
F_21, the force exerted by charge 1 on charge 2, PE the
electrostatic potential energy of the two charges relative to
infinite separation
(quantities
related to PE incorporated in asst 25)
23.03. Calculate the
potential energy change per unit of 'test charge' when moved through a small
displacement in the vicinity of a system consisting of two charges.
Technically:
Relate
{Q, q1, q2, (x_1, y_1), (x_2, y_2), (x, y),
r_1, r_2,
F_1, F_2, F, F / Q, PE, PE / Q}
where (x, y) is a
position different from the positions of q_1 and q_2, Q a
hypothetical charge located at (x, y), r_1 and r_2 the
vectors from q_1 and q_2, respectively, to (x, y), F_1 and F_2 the forces exerted on Q by q_1 and q_2,
F (quantities
related to PE incorporated in asst 25)
23.04. Calculate the
potential energy change per unit of 'test charge' when moved
through a small displacement in the vicinity of a system
consisting of a number of charges.
Technically:
Relate
{q_i, (x_i,
y_i), F_i
| i = 1, ..., n} U {Q, (x, y),
F, E_i, E, PE_system}
where q_i is the ith of
n charges, (x_i, y_i) its position, F_i the force of the ith
charge and F the net force exerted by the n charges on the
charge Q at (x, y), PE_system the total
electrostatic potential energy of the n charges relative to infinite
separation, E_i the contribution of the ith charge to the
electric field at (x, y), E the electric field at (x, y) due
to the n charges.
|
Asst #23 |
Introductory Problem Set |
lab/activity |
text |
outline |
Class Notes |
other |
query |
|
23 |
Set 1, Probs 1-5 |
Collaborative_labs_II [10] |
|
|
Class Notes
#26 |
Physics I Initial Problem Sets: Vectors
Overview of Electrostatic Forces, Fields and Energy |
query_23
|
|
Assignment #24 Objectives
Assignment 24
Objectives Continue Assignment #23 Objectives
|
Asst #24 |
Introductory Problem Set |
lab/activity |
text |
outline |
Class Notes |
other |
query |
|
24 |
Set 1, Probs 6-9 |
PHeT
18.10 Balloons and Static Electricity |
text_24 |
|
Class Notes
#27 |
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query_24
|
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Assignment #25 Objectives
25.01.
Use the 'flux picture' to calculate the force per unit test
charge, due to a single actual charge, at a given distance from
that charge.
Technically:
Relate
for a sphere with a single point charge at its center, where phi is
the electrostatic flux through the sphere, Q the charge, a the
radius of the sphere, E the magnitude of the electric field at a
point on the surface of the sphere, q a charge at distance r from
the center, PE(r) the electrostatic potential energy of the system,
V(r) the electrostatic potential at the position of q due to the
charge Q.
{Q, phi, A, E, q, r, PE(r), V(r)}
25.02.
Calculate the change in electrostatic potential between two
points in a field that can be considered uniform between the
points.
Technically:
Relate
{F,
E, `ds, q, `dW_on,
`dPE_elec, `dV}
where F is
the force exerted on charge q at a certain position, E the
field at that position, `ds a displacement of q small enough
that the field E does not change significantly, `dPE_elec the
change in the electostatic potential energy due to the displacement
of q, `dW_on the done on q by the field during the displacement, `dV
the change in electrostatic potential between the initial and final
positions of q
|
Asst #25 |
Introductory Problem Set |
lab/activity |
text |
outline |
Class Notes |
other |
query |
|
25 |
Set 1, Probs 10-23 |
PHeT
18.21 Electric Field of Dreams |
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|
Class Notes
#28 |
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query_25
|
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Assignment #26 Objectives
26.01.
Relate
for current I in a short segment of length `dL in a charge
carrier in the presence of magnetic field B, where `dF
is the force exerted by the field on the segment:
{I,
B, `dL, `dF}
26.02.
Relate
for a circuit element with resistance R, where I is the current
through the element and V the potential difference across the
element:
{I, R, V}
26.03.
Relate
{P, I, V, R}
for a circuit element with resistance R, where I is the current
through the element and V the potential difference across the
element, and P is the power required to maintain the current.
26.04.
Relate
for long cylinder carrying an axially symmetric charge distribution
of density lambda, where phi_E is the electrostatic flux of the
distribution, a its radius and E the magnitude of the electric field
at distance r from the cylinder (where the distance from the point
to the nearest end of the cylinder is much greater than r):
{Q_enclosed,
lambda, L, phi_E, a,
E, r}
26.05.
Relate
for
a plane distribution of constant charge density, at a point much closer to plane
than to any of its edges:
{`dA,
sigma, `dQ, phi_E,
N, E}
where sigma is
the charge density, N a vector normal to the surface, `dA is the area of a cross section in a plane perpendicular to N
of an appropriately positioned rectangular 'box' all of whose
points are much closer to the plane than to any of its edges, `dQ
the charge enclosed in the box, phi_E the electrostatic flux through
an end of the box and E the electric field at the point.
26.06.
Relate
for
a parallel-plate capacitor in air, where A is the area of each
plate, d the separation, E the electric field between the plates, V
the potential difference between the plates, C the capacitance and Q
the magnitude of the
charge on each
plate:
26.07.
Relate
for two
conducting elements of the same material, each of constant
cross-section both subject to the same potential difference V
between its ends:
{A_cs_1, A_cs_2, I_1, I_2, L_1, L_2}
where A_cs
indicates cross-sectional area, I current, L length of the
conductor in the direction normal to the cross-section.
|
Asst #26 |
Introductory Problem Set |
lab/activity |
text |
outline |
Class Notes |
other |
query |
|
26 |
Set 2, Probs 1-5 |
Current Flow and Energy
[3]
PHeT
21.42 Circuit Construction Kit DC, 23.10 Faraday's
Electromagnetic Lab |
text_26 |
|
Class Notes
#22 |
|
query_26
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|
Asst |
Introductory Problem Set |
lab/activity |
text |
outline |
Class Notes |
other |
query |
|
Assignment #27 Objectives
27.01.
Relate
{C, Q, I, R, V_s, V_c, `dt, `dQ,
`dV_c},
for a series circuit consisting of a
source, a capacitor and a resistance element, with V_s is the
voltage of the source, C the capacitance, Q the charge on the
capacitor, V_c the voltage of the capacitor, I the current, R the
resistance, `dt a short time interval, `dQ the change in the charge
on the capacitor, `dV_c the change in the voltage across the
capacitor.
27.01.
Relate
{V, R_1, R_2, `dV_1, `dV_2, I_1,
I_2}
for a series or a parallel circuit with
two resistance elements, where V is the voltage of the course, R_1
and R_2 the two resistances, `dV_1 and `dV_2 the respective voltage
drops, I_1 and I_2 the currents through the respective resistors.
|
Asst #27 |
Introductory Problem Set |
lab/activity |
text |
outline |
Class Notes |
other |
query |
|
27 |
Set 3, Probs 1-6 |
Capacitors and Current, Voltage and Energy [3]
PHeT
25.53 Circuit Construction Kit AC |
text_27 |
|
Class Notes
#30, 31 |
|
query_27
|
|
Assignment #28 Objectives
28.01.
Relate
for short current segment `dL, position r relative to
`dL, the magnetic field contribution `dB at that
position; theta is the angle of `dL with respect to r
{`dL, `dB, I,
r,
theta}
28.02.
Relate
{I, orientation, a, B} for a circular current
loop of radius a in which a current I flows with a given
orientation, B the magnetic field at the center of the loop.
28.03.
Relate
for a plane region of area A, electric field of magnitude E whose
angle with respect to the specified normal of the plane is theta, phi_E the flux of the electric field through the region
{E, theta, A, phi_E}
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Asst #28 |
Introductory Problem Set |
lab/activity |
text |
outline |
Class Notes |
other |
query |
|
28 |
Set 4, Probs 1-7 |
Batteries, Circuits and Measurement of Voltage and Current. [3] |
text_28 |
|
Class Notes
#22 |
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query_28
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Asst |
Introductory Problem Set |
lab/activity |
text |
outline |
Class Notes |
other |
query |
|
Assignment #29 Objectives
29.01. Solve problems related to voltage
induced by changing magnetic flux.
29.02. Explain self-induction.
29.03.
Relate
for a plane region of area A, magnetic field of magnitude B whose
angle with respect to the specified normal of the plane is theta,
phi_B the flux of the magnetic field through the region
{B, theta, A, phi_B}
29.04.
Relate
for a plane region of area A, magnetic field of magnitude B whose
angle with respect to the specified normal of the plane changes from
theta_1 to theta_2 it time interval `dt, phi_B_1 the flux of
the magnetic field through the region at the beginning of the
interval and phi_B_2 the same quantity at the end, `dPhi_B the
change in flux, ave_Rate the average rate of change of flux with
respect to clock time, V_ave the approximate average induced
voltage:
{B, theta, A, phi_B_1, phi_B_2, `dPhi_B, ave_Rate, V_ave}
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Asst #29 |
Introductory Problem Set |
lab/activity |
text |
outline |
Class Notes |
other |
query |
|
29 |
Set 4, Probs 8-13 |
Charging and Discharging a Capacitor. [3] |
text_29 |
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Class Notes
#23 |
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query_29
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Assignment #30 Objectives
30.01.
Relate
for charge q moving with velocity v in electric field
E
and magnetic field B, where F_E and F_B are the
forces exerted by the respective fields
{q, E, B, v,
F_E, F_B}
30.02.
Relate
for segment `dL carrying current I, in the presence of
magnetic field B, where `dF is the force exerted on
the segment,
{`dL, B, I, `dF
}
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Asst #30 |
Introductory Problem Set |
lab/activity |
text |
outline |
Class Notes |
other |
query |
|
30 |
Set 4, Probs 14-18 |
The RC Circuit [3] |
text_30 |
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Class Notes
#24,25 |
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query_30
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Assignment #31 Objectives Continue mastery of previous objectives. |
Asst #31 |
Introductory Problem Set |
lab/activity |
text |
outline |
Class Notes |
other |
query |
|
31 |
Set |
|
text_31 |
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Class Notes
#31, 32 |
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query_31
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Assignment #32 Objectives Continue mastery of previous objectives. |
Asst #32 |
Introductory Problem Set |
lab/activity |
text |
outline |
Class Notes |
other |
query |
|
32 |
Set |
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Assignment #33 Objectives Continue mastery of previous objectives.
Complete review of Assignments 23-33. Test #3 should be
completed after Assignment 33. |
Asst #33 |
Introductory Problem Set |
lab/activity |
text |
outline |
Class Notes |
other |
query |
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33 |
Set |
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Module 4, Assignments 34 -
40
"Modern" Physics
·
Time dilation, length contraction, mass-energy.
·
Photoelectric effect, quantization of energy.
·
Uncertainty principle.
·
Atomic spectra, quantization of angular momentum, atomic structure.
·
Modes of nuclear decay, energy conservation.
|
Quantization of Energy in Electromagnetic Radiation:
-
c = `lambda * f:
Light, and generally all
electromagnetic radiation,
is characterized by a
uniform speed c
of approximately
3 * 10^8 m/s
in a vacuum, and by a
spectrum
of
wavelengths
`lambda, which can be
measured
using
diffraction gratings
and
photographic plates.
Frequencies are easily determined once wavelengths are measured.
-
E = h * f:
The
photoelectric effect
demonstrates that
electromagnetic radiation
with
frequency f
transfers
energy
in
discrete amounts
equal to the
product
of
Planck's constant
h = 6.63 * 10^-34 J s and the
frequency
of the radiation. In this sense electromagnetic radiation
behaves as a stream of
photons,
particles which carry
energy
but which have
no mass.
-
p = E / c:
A
photon
with
energy E
will have
momentum p = E / c.
Wave Properties of Particles:
-
`lambda = h / p:
A beam of massive
particles
(i.e., particles with mass) each with
momentum p
will exhibit
interference effects
identical to those of a wave having
wavelength `lambda = h / p,
where h is Planck's constant. This wavelength `lambda is called
the
deBroglie
wavelength.
-
`dx * `dp
= h
(uncertainty principle): The
uncertainty
in x, the
position
of an object, and p, the
momentum
of the object, are denoted by
`dx
and
`dp.
It is
not possible
to
measure
both
position and momentum
to an
arbitrarily high degree
of
precision.
The more precisely one is measured the less precisely is
possible to determine the other. The
product
of the
uncertainties
is approximately equal to
Planck's constant.
i.e., `dx * `dp
= h.
Quantization of Orbital Energies in Atoms:
-
m
v^2 / r = k q^2 / r^2
(condition relating velocity and radius of 'orbit' of electron
around proton). If an
electron 'orbits' a proton
at a
distance r,
then the
velocity
must be such that the
Coulomb attraction
k q^2 / r^2 (q = charge of electron) between the proton and
electron constitutes the
centripetal force
m v^2 / r required to maintain the circular path. This
relationship can easily be
solved
for
v in terms of r,
obtaining r = k q^2 / (m v^2).
-
m
* v * r = n ( h / (2 `pi) ),
n = 1, 2, 3, ... . (quantization
condition for angular momentum): Angular momentum can occur only
in whole-number multiples of h / ( 2 `pi ). Combining this
quantization condition
on the angular momentum m * v * r with
m v^2 / r = k q^2 / r^2
we conclude that for an electron orbiting a proton,
only certain orbital radii
and their associated velocities and energies can occur. The
resulting
model explains
to a high degree of precision the
spectrum
observed as a result of energy transitions within a hydrogen
atom.
-
r = n^2 h^2 / ( 4 `pi^2 k q^2 m)
= n^2 * .509 *10^-10 m approx., n = 1, 2, 3, ... . (possible
radii of electron orbit around proton)
Combining
m v r = n ( h / (2 `pi) ), the
quantization condition
on angular momentum, with m v^2 / r = k q^2 / r^2, which states
that
Coulomb Force = centripetal force,
we obtain r = n^2 h^2 / ( 4 `pi^2 k q^2 m). Using h = 6.63 *
10^-34 J s, k = 9 * 10^9 N m^2 / C^2, q = 1.60 * 10^-19 Coulombs
and m = 9.11 * 10^-31 kg (mass of electron) we find that h^2 /
( 4 `pi^2 k q^2 m) = .509 * 10^-10 m,
approx., so we can write
r = n^2 * .509 Angstroms
(approx). An Angstrom is 10^-10 meter.
-
2 `pi r = n * `lambda
(orbital radius contains an integer number of particle waves):
For an
orbital radius
satisfying the
quantization condition,
the
circumference
of the orbital is a
whole number
of
deBroglie
wavelengths,
suggesting that the electron in
forms allowed orbits
by
creating a standing wave in each.
Conversion between Mass and Energy and Nuclear Decay Modes:
-
E = m c^2:
As predicted by Special Relativity and as confirmed by
experiment,
mass
can be converted to
energy
and vice versa. The
energy equivalent
to
mass m
is E = m c^2.
-
Alpha decay
consists of the
emission
of a
helium nucleus
(2 protons and 2 neutrons all bound together) from the nucleus
of a
larger atom
(i.e., one containing in its nucleus more than 2 protons and 2
neutrons). This process
reduces
the number of
protons
and
neutrons
in the larger nucleus
each by 2.
The
mass
of the
resulting nucleus
plus the
mass
of the
alpha particle
is
less than
the
mass
of the
original nucleus.
The resulting
mass defect
appears in the form of
kinetic energy
as the alpha particle and the remains of the original nucleus
fly apart
in opposite directions. In the usual case, where the
alpha particle
is
much less massive
then the remains of the
original nucleus,
almost all of this
kinetic energy
resides in the
alpha particle.
-
Beta decay
consists of the
emission
of an
electron
from the
nucleus
of an atom. This process results when a
neutron
decays into a
proton
and an
electron
(note that the
total charge is conserved--the
original neutron has zero charge, and a proton and an electron
have a net charge of zero). This process thus
increases
the number of
protons
in the nucleus
by 1
and
reduces
the number of
neutrons
by 1. The
mass
of the
resulting nucleus
plus the
mass
of the
beta particle
(the electron) is
less
than the mass of the
original nucleus.
The resulting
mass defect
appears in the form of
kinetic energy
as the electron and the new nucleus fly apart in opposite
directions. Since the
electron
is
very much less massive
then the new nucleus, virtually all of this
kinetic energy
resides in the
electron.
-
Gamma decay
is
analogous
to a
decrease
in the
orbital energy
of an electron in an atom, but Gamma decay takes place
within the nucleus
and involves
nuclear particles.
The
energies
within the nucleus are
much higher
than the energies of
atomic electrons,
and the energies of the
Gamma photons
are hence
much greater
than the energies emitted by
atomic electrons.
The
nucleus
after a Gamma decay is
less massive
than before, and the
mass defect
is carry off by the
energy
of the
photon.
Special Relativity:
-
`dt ' = `dt
* 1 / (1 - v^2 / c^2)
(time dilation): Einstein's Theory of
Special Relativity
is based on the assumption that the
laws of physics
are the
same
in
all interial reference frames.
One consequence of these laws is that the
speed of light
in a
vacuum
is
c = 3 * 10^8 m/s,
approx.. If we consider a
photon
bouncing
back and forth
in the
vertical direction
between
two mirrors
in a
spaceship
which passes at
velocity v
in the
horizontal direction,
we are led to the conclusion that the
time between round trips
as measured by an
occupant
of the
spaceship
will be
different
than the
time between round trips
as measured from
our frame of referencet.
Specifically if in
our frame of reference
we measure a
time interval `dt '
between
two events
which occur at the
same location
as observed by the occupants of the
passing spaceship
while the occupants of the
spaceship
measure
time interval `dt,
our time interval
`dt '
will be
greater than `dt
by
factor 1 / (1 - v^2 /c^2).
The
contraction of length
and the
increase of mass,
as well as the
relative nature of simultaneity,
also follow (see below).
-
`dx ' = `dx
* `sqrt(1 - v^2 / c^2)
(length contraction): If a
spaceship
passes us moving moving at
velocity v
relative to our frame of reference, and if as measured by the
occupants
of the ship its
length
in the direction of its velocity is
`dx,
then the most accurate measurements
in our frame of reference
will determine that the
length
of the ship is
`dx
' , which is
less
than `dx by
factor `sqrt(1 - v^2 / c^2).
-
m ' = m * 1 / `sqrt( 1 - v^2 / c^2)
(relativistic mass): If a
spaceship
passes us moving moving at
velocity v
relative to our frame reference has
mass m,
as measured by the occupants of the spaceship (who could, for
example, measured the acceleration and the net force applied to
the spaceship to determine its mass), then any measurement made
in
our frame of reference
to determine the mass will indicated that the
mass is m '
, which is
greater than m
by the
factor 1 / `sqrt(1 - v^2 / c^2).
-
Relative nature of simultaneity:
If a
spaceship
passes us moving moving at
velocity v
relative to our frame reference, then two events that occur
simultaneously
but at
different locations
as measured by the occupants of the
spaceship
will
not occur simultaneously
in
our
reference frame.
-
KE = m c^2 / `sqrt(1
- v^2 / c^2 ) - m c^2.
If a
spaceship
with
mass m,
as measured in the frame of reference of the spaceship, passes
us moving moving at
velocity v
relative to our frame reference, then its
kinetic energy
will be m c^2 / `sqrt(1 - v^2 / c^2
) - m c^2. For
velocities v
which are
small
compared to c, this expression reduces to
.5 m v^2.
The expression for kinetic energy can also be written by
factoring
the
m c^2
out, obtaining
m c^2 ( 1 / `sqrt(1-v^2/c^2)
- 1).
This form suggests a
'rest energy'
of
m c^2,
to which kinetic energy is added as velocity increases.
-
Correspondence Principle:
The Correspondence Principle states that the
results of relativistic mechanics reduce,
at
small relative velocities
v, to the
results of classical Newtonian mechanics.
Stated another way, there must be a smooth transition from the
everyday physics of low relative velocities to the relativistic
physics of high relative velocities.
Brief Notes about Particle Physics:
-
If a
particle
such as a proton or and electron is
accelerated,
usually by means of electromagnetic forces, to a
high relativistic velocity
then the possibility exists that the
total energy
of the particle can be
converted
to
other particles.
This usually happens when the
particle interacts
with
other particles.
The
rest mass
of the particles so created can
exceed
the
rest mass
of the
original particles
as some of the
kinetic energy
of the original particles
converts to mass.
This conversion satisfies the equation
E = m c^2.
-
When
new particles
are created a number of
conservation laws
apply. The
total energy
of the particles involved is the
same before
as
after collision,
provided we
include
the energy equivalent
E = m c^2
of the
rest mass
of the particles as part of the energy.
Momentum
must be
conserved
(keeping in mind that we're talking about relativistic momentum
m v * 1 / `sqrt(1-v^2/c^2).
Electric charge
must be
conserved
(for example the total charge after a collision involving a
proton and a neutron must be the same, +1, as before the
collision).
Other
more subtle
conservation laws
also apply. These conservation laws lead to a
classification
of the hundreds of different particles observed and of their
properties. This
classification
leads to a very successful
mathematical model
which successfully
predicts
the
nature of particles
prior to their being observed. This model is called the
Quark Theory.
-
It is believed that
protons,
neutrons
and
hundreds of other particles
are in fact combinations of
more fundamental particles
called
Quarks.
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Assignment #34 Objectives
34.01. Solve problems involving the particle
nature of light and the wave nature of particles.
34.02.
Apply the uncertainty principle to approximate the
characteristics of an electron confined to the vicinity of a proton,
and a proton confined within a nucleus.
34.03.
Relate
where h is Planck's Constant, f the frequency of electromagnetic
radiation, lambda its wavelength and c its propagation velocity
{h, f, c, lambda, photon energy,
photon momentum}
34.04.
Relate
where m, v, KE and p are the mass, velocity, kinetic energy and
momentum of a particle and lambda its deBroglie wavelength
{m, v, KE, p, lambda, h}
34.05.
Relate
where `dp, `dx and `dv are the uncertainties in momentum position
and velocity of a particle, m its mass
{`dp, `dx, `dv, m, h}
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Set 7, Probs 1-6 |
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Assignment #35 Objectives
35.01.
Relate
for an electron in a classical circular orbit about a proton, where
m_e is the mass of electron, v its oribtal velocity, r its distance
from the proton, F_coul the Coulomb attraction between the
particles, F_centrip the classically-predicted centripetal force, KE
and PE the kinetic and potential energies of the orbit (PE relative
to infinite separation)
{m_e, v, KE, r, F_coul,
F_centrip}
35.02. Relate
for the preceding situation with the additional quantization
condition on angular momentum, where lambda and circumf are the
deBroglie wavelength of the electron and circumf the circumference
of the classical orbit
{m_e, v, KE, PE, r, F_coul,
F_centrip, n, angular momentum, lambda, circumf}
35.03. Relate
where n_1 and n_2 are angular momentum quantum numbers, `dKE and `dPE
the kinetic and potential energy changes for the Bohr model of the
hydrogen atom, f the frequency of the photon associated with the
change in orbit
{n_1, n_2, `dKE, `dPE, f}
35.04. Relate
where E is the energy equivalent of mass m and c the speed of light
{E, m, c}
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Set 7, Probs 7-12 |
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#35 |
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Assignment #36 Objectives
36.01. Analyze masses of two given isotopes of a
given element to determine if a given transition is possible.
36.02. Given the information in a periodic table of elements and
their isotopes, identify possible decay chains involving alpha, beta
and gamma decays.
36.03. Relate
where E is the energy equivalent of mass m and c the speed of light,
lambda the wavelength of a photon with equivalent energy
{E, m, c, lambda}
36.04. Relate
where N_p is the number of protons and N_n the number of neutrons in
a nucleus, m_p and m_n the masses of proton and neutron (masses in
SI units, AMU or equivalents), m_nucleus the mass of the nucleus, '
indicates properties of the resulting nucleus after a nuclear
transition, m_defect the mass defect associated with the transition
and E the energy released by the transition:
{N_p, N_n, m_p, m_n, m_nucleus,
N_p', N_n', m_p, m_n, m_nucleus', E}
36.05. Relate
where N_p is the number of protons and N_n the number of neutrons in
a nucleus, ' indicates properties of the resulting nucleus after a
nuclear transition, and transitionType indicates the type of
transition (alpha, beta, gamma)
{N_p, N_n, N_p', N_n',
atomicNumber, atomicNumber', transitionType}
36.06. Relate
where all quantities have been defined in preceding objectives
{N_p, N_n, N_p', N_n', m_p, m_n,
m_particle, atomicNumber, atomicNumber', transitionType}
36.07. Relate
where E_bind is total binding energy, E_per is binding energy
per nucleon, other quantities as previously defined:
{E_bind, E_per, m_p, m_n,
m_nucleus}
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Asst #36 |
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query |
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36 |
Set 7, Probs 13-19 |
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Class Notes
#36 |
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Assignment #37 Objectives
37.01. Relate
where v is the relative velocity of two reference frames, L and L '
the lengths of a given object as measured in the two frames, `dt and
`dt' the time interval between two events as measured in the two
frames, m and m ' the masses of a given object as measured in the
two frames:
{v, c, L, L', `dt, `dt', m, m'}
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Set 7, Probs 20-23 |
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Assignment #38 Objectives
Continue mastering previous objectives, review. |
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Set 7, Probs 24-27 |
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Assignment #39 Objectives
Continue mastering previous objectives, review.Complete
Test #4. This test must be in the instructor's possession by
the end of the last day of Final Exams. |
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lab/activity |
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outline |
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other |
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40 |
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