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PHY 231
Your 'cq_1_03.1' report has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.
** CQ_1_03.1_labelMessages.txt **
The problem:
A ball starts with velocity 0 and accelerates uniformly down a ramp of length 30 cm, covering the distance in 5 seconds.
What is its average velocity?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
30 cm / 5 sec = 6 cm/sec
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If the acceleration of the ball is uniform then its average velocity is equal to the average of its initial and final velocities.
You know its average velocity, and you know the initial velocity is zero.
What therefore must be the final velocity?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
(Initial + final) / 2 = 6 cm / sec :::
0 + final = 12 cm/sec :::
final = 12 cm/sec
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By how much did its velocity therefore change?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
0 cm / sec to 12 cm / sec = 12 cm/sec change
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At what average rate did its velocity change with respect to clock time?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
12/5 cm/sec change in one second
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You need to divide the 12 by the 5, which will give you 2.4. You also need to divide the units of the 12 by the units of the 5 to get the concise expression for the units of the result.
Your interpretation, that this is the cm/s change in one second, is appropriate, correct and insightful. However we do also need the more concise expression of the unit.
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What would a graph of its velocity vs. clock time look like? Give the best description you can.
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
A line with a positive slope
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Very good answers to most questions, and good insights.
I am asking for some revision, which you should have no trouble doing in a short time.
&#Please see my notes and submit a copy of this document with revisions, comments and/or questions, and mark your insertions with &&&& (please mark each insertion at the beginning and at the end).
Be sure to include the entire document, including my notes. &#
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