query1 

course phy201

2/07/2010 1:49

ph1 query 1*********************************************

Question: `qExplain in your own words how the standard deviation of a set of numbers is calculated.

YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY

Your solution:

The standard deviation of a set of number is calculated by first squaring all the numbers or

deviations obtained, then average the squared numbers (deviations), take the square root of the

average of the numbers (deviations).

confidence rating #$&*3

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

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@

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

Question: Explain in your own words the process of fitting a straight line to a graph of y vs. x

data, and briefly discuss the nature of the uncertainties encountered in the process. For example,

you might address the question of how two different people, given the same graph, might obtain

different results for the slope and the vertical intercept.

YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY

Your solution:

The process of fitting a straight line to a graph of y vs x is that you must fit the straight line as

best you can so that it pas through, but does not touch the data points given. The y intercept is the

point on the y axis in which that line touches. Uncertainties are encountered from person to person

when obtaining this information because one persons line may vary in steepness or where it lands on

the y axis from another persons.

confidence rating #$&*2

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

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@

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

Question: Briefly state what you think velocity is and how you think it is an example of a rate.

YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY

Your solution:

velocity is the change in rate from one point to another. You can find an objects velocity by

subtracting the objects starting point from the point at which the object stops and dividing that from

the time it took the object to travel that change in distance.

confidence rating #$&*3

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

@@@@@@@@@@@@@@@

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

Given Solution:

A rate is a change in something divided by a change in something else.

This question concerns velocity, which is the rate of change of position: change in position divided

by change in clock time. **

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

Self-critique (if necessary):3

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@

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

Question: Given average speed and time interval how do you find distance moved?

YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY

Your solution:

To find the aveage distance you multiply the average speed by the time interval

confidence rating #$&*3

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

@@@@@@@@@@@@@@@@@@@

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

Given Solution:

** You multiply average speed * time interval to find distance moved.

For example, 50 miles / hour * 3 hours = 150 miles. **

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

Self-critique (if necessary):3

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@

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

Question: Given average speed and distance moved how do you find the corresponding time interval?

YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY

Your solution:

To find the corresponding time interval you would divide the distance moved by the average speed,

t= distance moved/ average speed

confidence rating #$&*3

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

@@@@@@@@@@@@@@@@@@@@@@

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

Given Solution:

** time interval = distance / average speed. For example if we travel 100 miles at 50 mph it takes 2

hours--we divide the distance by the speed.

In symbols, if `ds = vAve * `dt then `dt = `ds/vAve.

Also note that (cm/s ) / s = cm/s^2, not sec, whereas cm / (cm/s) = cm * s / cm = s, as appropriate in

a calculation of `dt. **

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

Self-critique (if necessary):3

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@

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

Question: Given time interval and distance moved how do you get average speed?

YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY

Your solution:

vave=ds/dt.......to get average speed you divide the distance moved by the given time.

confidence rating #$&*3

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

@@@@@@@@@@@@@@@@@@@@@@@@@@@@

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

Given Solution:

** Average speed = distance / change in clock time. This is the definition of average speed.

For example if we travel 300 miles in 5 hours we have been traveling at an average speed of 300 miles

/ 5 hours = 60 miles / hour. **

&#This looks very good. Let me know if you have any questions. &#