cq_1_022

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PHY 201

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.

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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?

The clock time would be (5s + 13s)/2 = 9 sec

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

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What is the velocity at the midpoint of this interval?

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

Velocity would be (16 cm/s + 40 cm/s)/2 = 28 cm/s

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How far do you think the object travels during this

interval?

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

average velocity * time

28 cm/s * 4 sec = 112 cm

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@& The interval lasted 8 seconds, not 4 seconds. Otherwise good.*@

By how much does the clock time change during this

interval?

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

The clock time changes by +4 seconds. 9 sec - 5 sec = 4

sec

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By how much does velocity change during this interval?

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

Velocity changes by 12 cm/s. 28 cm/s - 16 cm/s = 12

cm/s.

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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):

12 cm/s / 4 sec = 3 cm/s^2

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What is the rise of the graph between these points?

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

12 cm/s

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What is the run of the graph between these points?

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

4 sec

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What is the slope of the graph between these points?

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

+3

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@& The rise and run have units and meanings, which gives the slope units and meaning.*@

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 positive slope tells you the velocity of the object

is increasing.

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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):

12 cm/s / 4 sec = 3 cm/s^2

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*#&!

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