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Phy 231
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?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
13 sec - 5 sec = 8 seconds
8 seconds / 2 = 4 seconds
9 seconds is the midpoint
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• What is the velocity at the midpoint of this interval?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
40cm/s - 16cm/s = 26cm/s
26cm/s / 2 = 13cm/s
@& The midpoint velocity will be equally near the two endpoint velocities.
13 cm/s isn't even between the endpoint velociites.
You had an arithmetic error in your calculation; your calculations would have yielded half the change in velocity, which would be 12 cm/s.
Adding this to the initial velocity, or subtracting it from the final velocity, would give the midpoint velocity, as would averaging the initial and final velocities.*@
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• How far do you think the object travels during this interval?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
(16cm/s + 40 cm/s) / 2 = 56cm/s / 2 = 28cm/s
28cm/s * 8 sec = 224cm
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• By how much does the clock time change during this interval?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
8 seconds
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• By how much does velocity change during this interval?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
26cm/sec
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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):
26cm/sec / 8 sec = 3.25cm/sec^2
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• What is the rise of the graph between these points?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
26
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• What is the run of the graph between these points?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
8
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• What is the slope of the graph between these points?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
3.25
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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 says that the object is speeding up
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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):
3.25 cm/sec^2
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10 minutes
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5/15 3:15AM
@& You've got an arithmetic error, as well as a procedure error, among your calculations. You'll understand, so there's no need to submit a revision, but be sure to check my notes and the link below.*@
&#See any notes I might have inserted into your document, and before looking at the link below see if you can modify your solutions. If there are no notes, this does not mean that your solution is completely correct.
Then please compare your old and new solutions with the expanded discussion at the link
Solution
Self-critique your solutions, if this is necessary, according to the usual criteria. Insert any revisions, questions, etc. into a copy of this posted document. Mark any insertions with &&&& so they can be easily identified.If your solution is completely consistent with the given solution, you need do nothing further with this problem. &#