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PHY 231
Your 'cq_1_04.1' 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 ball is moving at 10 cm/s when clock time is 4 seconds, and at 40 cm/s when clock time is 9 seconds.
• Sketch a v vs. t graph and represent these two events by the points (4 sec, 10 cm/s) and (9 s, 40 cm/s).
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
I graphed (4 sec, 10 cm/s) and (9 s, 40 cm/s) with time along the x axis and position along the y axis.
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• Sketch a straight line segment between these points.
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
I also sketched the straight line between points. (Increasing to the right)
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• What are the rise, run and slope of this segment?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
Rise = 40cm-10 cm= 30 cm
Run = 9s-4s = 5s
Slope = 30cm/5s = 6 cm/s
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@& 30 cm is not a quantity associated with this situation.
30 cm/s is.
The vertical coordinates are in cm/s, not cm. So the rise is in cm/s.
This changes the units of the slope.
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• What is the area of the graph beneath this segment?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
.5(40 cm + 10 cm) * 5 s
125 cm
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@& 25 cm * 5 s = 125 cm * s, not 125 cm.
You don't have the right units on your vertical quantities.
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*#&!
@& You're doing things pretty much correctly, but you need to pay closer attention to units, which among other things reflect the meanings of your quantities and help make sense of your calculations.
&#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. &#
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