query13

#$&*

course mth 173

7/28 2

If you are unable to attempt a solution, give a phrase-by-phrase interpretation of the problem along with a statement of what you do or do not understand about it.  This response should be given, based on the work you did in completing the assignment, before you look at the given solution. 

013. `query 13

 

 

*********************************************

Question: `q query problem 2.3.37 . Which graph matches the graph of the bus and why?

 

YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY

Your solution:

 

graph one shows a car that reaches a constant velocity so this must be matched with the car that has all green lights.

graph 3 shows a car that never reaches a relatively high velocity and is equivalent to a car in heavy traffic conditions.

So graph 2 must be the bus and the up and down in velocity must indicate red lights or stop signs.

 

 

confidence rating #$&*: 3

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

.............................................

Given Solution:

 ** The bus only makes periodic stops, whereas the graph for III only comes to a stop once. I would matche the bus with II. **

 

&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&

Self-critique (if necessary):

 

 

 OK

 

 

------------------------------------------------

Self-critique Rating:

OK

*********************************************

Question: `q describe the graph of the car with no traffic and no lights

 

YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY

Your solution:

 

The graph increases at a decreasing rate until the car reaches a constant velocity.

 

confidence rating #$&*:

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

3

.............................................

Given Solution:

 ** The car matches up with (I), which is a continuous, straight horizontal line representing the constant velocity of a car with no traffic and no lights. *&*&

 

 

&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&

Self-critique (if necessary):

 

 

 In my 5th edition book it is not a linear line but instead the one I described before. It represents a car that accelerates at a decreasing rate until it reaches a maximum sustained speed.

 

 

------------------------------------------------

Self-critique Rating:

3

*********************************************

Question: `q describe the graph of the car with heavy traffic

 

YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY

Your solution:

 

 

It is a curved that has multiple points of both positive and negative concavity representing a car doing a lot of slowing down and speeding up.

 

 

confidence rating #$&*:

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

3

.............................................

Given Solution:

 ** The car in heavy traffic would do a lot of speeding up and slowing down at irregular intervals, which would match the graph in III with its frequent increases and decreases. **

 

&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&

Self-critique (if necessary):

 

 

 OK

 

 

------------------------------------------------

Self-critique Rating: OK

*********************************************

Question: `q query 2.4.11 5th, 2.4.10 4th; 2.5.10 (was 2.4.8) q = f(p) (price and quantity sold)what is the meaning of f(150) = 2000?

 

YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY

Your solution:

f(150) = 2000 means that a price of $150 a 2000 units of the item will be sold.

 

confidence rating #$&*:

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

3

.............................................

Given Solution:

 *&*& q = 2000 when p = 150, meaning that when the price is set at $150 we expect to sell 2000 units. *&*&

 

&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&

Self-critique (if necessary):

 

 

 OK

 

 

------------------------------------------------

Self-critique Rating: OK

*********************************************

Question: `q what is the meaning of f'(150) = -25?

 

 

 

YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY

Your solution:

 

 at a price of $150 the number of units sold will be changing at -25 units/$

 

 

confidence rating #$&*: 3

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

.............................................

Given Solution:

 ** f' is the derivative, the limiting value of `df / `dp, giving the rate at which the quantity q changes with respect to price p.

 

If f'(150) = -25, this means that when the price is $150 the quantity will be changing at a rate of -25 units per dollar of price increase.

 

Roughly speaking, a one dollar price increase would result in a loss of 25 in the number sold. **

 

&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&

Self-critique (if necessary):

 OK

 

 

------------------------------------------------

Self-critique Rating:

OK

*********************************************

Question: `q query problem 2.4.23 5th; 2.4.18 4th; 2.4.7 graph of v vs. t for no parachute.

 

Describe your graph, including all intercepts, asymptotes, intervals of increasing behavior, behavior for large |t| and concavity, and tell why the graph's concavity is as you indicate.

 

 

YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY

Your solution:

the y intercept is (0,0) and the x intercept is (0,0). the graph increases at a decreasing rate (concave down) until

the terminal velocity is reached at which point the velocity will remain constant and the line will be y = terminal velocity. There is a horizontal asymptote at the terminal velocity.

 

 

confidence rating #$&*: 3

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

.............................................

Given Solution:

 ** When you fall without a parachute v will increase, most rapidly at first, then less and less rapidly as air resistance increases.

 

When t = 0 we presume that v = 0.

 

The graph of v vs. t is therefore characterized as an increasing graph beginning out at the origin, starting out nearly linear (the initial slope is equal to the acceleration of gravity) but with a decreasing slope. The graph is therefore concave downward.

 

At a certain velocity the force of air resistance is equal and opposite to that of gravity and you stop accelerating; velocity will approach that 'terminal velocity' as a horizontal asymptote.

 

The reason for the concavity is that velocity increases less and less quickly as air resistance increases; the approach of the velocity to terminal velocity is more and more gradual **

 

 

&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&

Self-critique (if necessary):

 

 

 OK

 

 

------------------------------------------------

Self-critique Rating:

OK

*********************************************

Question: `q What does the t = 0 acceleration indicate?

 

 

YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY

Your solution:

 

the acceleration due to gravity.

 

 

confidence rating #$&*:

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

.............................................

Given Solution:

 ** t = 0 acceleration is acceleration under the force of gravity, before you build velocity and start encountering significant air resistance.

 

Acceleration is rate of velocity change, indicated by the slope of the v vs. t graph. **

 

STUDENT QUESTION

 

 I understand how acceleration and vel. are related, just not the first part of solution

 

INSTRUCTOR RESPONSE

 

If it wasn't for air resistance, acceleration would be equal to that of gravity.
When you first jump out you aren't falling very fast, so there isn't much air resistance to counter the acceleration of gravity, so you accelerate pretty much at the acceleration of gravity.
You quickly speed up, and air resistance becomes more and more significant. So your acceleration becomes less than the acceleration of gravity.
Assuming the ground is far away, this continues until air resistance is effectively equal to the force of gravity, at which point your acceleration will be zero. You will be at terminal velocity.

 

&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&

Self-critique (if necessary):

 OK

 

 

------------------------------------------------

Self-critique Rating: OK

*********************************************

Question: `q Query Add comments on any surprises or insights you experienced as a result of this assignment.

 

 

&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&

Self-critique (if necessary):

 

One thing I think i can guess is that the area underneath an acceleration vs t graph is = to the change in velocity.

@&

That is correct.

*@

 

 

------------------------------------------------

Self-critique Rating:"

Self-critique (if necessary):

------------------------------------------------

Self-critique rating:

Self-critique (if necessary):

------------------------------------------------

Self-critique rating:

#*&!

&#Good responses. See my notes and let me know if you have questions. &#