cq_1_022

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Phy 121

Your 'cq_1_02.2' report has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.

** CQ_1_02.2_labelMessages **

The problem:

A graph is constructed representing velocity vs. clock time for the interval between clock times t = 5 seconds and t = 13 seconds. The graph consists of a straight line from the point (5 sec, 16 cm/s) to the point (13 sec, 40 cm/s).

• What is the clock time at the midpoint of this interval?

answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):

The midpoint of this interval is (9 sec, 28cm/s).

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• What is the velocity at the midpoint of this interval?

answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):

The velocity at the midpoint of this interval is 28cm/s because 40+16=56/2=28.

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• How far do you think the object travels during this interval?

answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):

224cm because they are traveling at an average velocity of 28cm/s for 8 seconds and 28*8=224.

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• By how much does the clock time change during this interval?

answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):

The clock time changes by 8 seconds during this interval because 13-5=8.

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• By how much does velocity change during this interval?

answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):

The velocity changes by 24cm/s because 40-16=24.

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• What is the average rate of change of velocity with respect to clock time on this interval?

answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):

The average rate of change of velocity is 3cm/s because 24/8=3.

@&

Your units aren't right here.

You need to use units throughout the calculation, and actually do the algebra of the units.

*@

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• What is the rise of the graph between these points?

answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):

The rise of this graph is 24 because 40-16=24.

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• What is the run of the graph between these points?

answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):

The run of this graph is 8 because 13-5=8.

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• What is the slope of the graph between these points?

answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):

The slope of the graph is 3 because 24/8=3.

@&

There are units with these quantities as well..

*@

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• What does the slope of the graph tell you about the motion of the object during this interval?

answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):

The slope of the graph tells us that the object moves forward at an increasing rate during this time interval.

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• What is the average rate of change of the object's velocity with respect to clock time during this interval?

answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):

The average rate of change of velocity with respect to the clock time interval is 3cm/s because 24/8=3.

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@&

Excellent application of the definitions.

The only problem is your units, which are pretty much wrong or missing on most of your last several answers.

Check my notes. I don't think you'll have any trouble with this.

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