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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?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
The clock time at the midpoint of the interval would be 9. This justified in two ways you can say that 9 is the number in between 5-13 ….5 6 7 8 9 10 11 12 13, or by taking the average and saying that 5 + 13 = 18 / 2 = 9. This is the way I would think you would find the midpoint, but is this the right way and is there another way of finding is.
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• What is the velocity at the midpoint of this interval?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
For this question would it be correct to use the change of velocity formula and say that (40cm/sec) – (16 cm/sec) / (13sec) – (5sec) = 24cm/sec / 8sec = 3cm/sec/sec? No know I see the ending answer I do not think that is right.
So could average the numbers again like for the first question. 5 + 13 = 18 / 2 = 9sec and 40 + 16 = 56 / 2 = 28cm/sec
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• How far do you think the object travels during this interval?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
Using the starting points and the ending points I would take 40cm/sec and subtract it by 16cm/sec to equal 24cm/sec. Then take 13sec and subtract it by 5sec to equal 8sec. Since the object travel for 8sec between point A and point B at a velocity of 24cm/sec, I would multiply 24 * 8 = 192 cm
24 cm/s is the change in velocity. The distance traveled doesn't depend directly on the change in velocity. For example you can go a long way traveling at 70 mph; no change in velocity is required.
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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 8sec 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):
Velocity changes by 24cm/sec 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):
Average rate of change of velocity is :
(40cm/sec) – (16 cm/sec) / (13sec) – (5sec) = 24cm/sec / 8sec = 3cm/sec/sec
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• What is the rise of the graph between these points?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
The graph has a positive Rise. Because the graph runs in a upward direction.
you can give a specific quantitative answer to this question.
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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 the graph is positive because it would go to the right.
you can give a specific quantitative answer to this question.
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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 would be the distance between the two points in the y direction / the distance between the two points in the x direction.
you can give a specific quantitative answer to this question.
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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):
That as the time progresses the velocity of the object speeds up going faster and faster.
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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):
I am uncertain as to answer this question. I understand that you are asking for the average change in rate of the velocity: (40cm/sec) – (16 cm/sec) / (13sec) – (5sec) = 24cm/sec / 8sec = 3cm/sec/sec. But I am unsure as to how to relate it with clock time. I am confused as to what the question is actually asking for. Not to say that the question is poorly worded but saying I do not fully comprehend.
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About 30 min
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You had good answers to some questions. On others you needed quantitative answers, and on some your reasoning was close but not quite correct.
&#See any notes I might have inserted into your document. If there are no notes, this does not mean that your solution is completely correct.
Then please compare your 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. &#