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Phy 121
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.
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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):
vAve= distance/ time
vAve= 30 cm/ 5sec
=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):
The final velocity is 6 cm/ sec.
??? Is the two questions the same answer since the initial velocity is 0?
@& If initial velocity is 0 and final velocity is 6 cm/s, then the average velocity would be 3 cm/s.
However the average velocity is 6 cm/s, as you found previously.
So the final velocity is not 6 cm/s.*@
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• By how much did its velocity therefore change?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
It change by 6cm/ sec.
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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):
Rate of change of A with respect to B
6cm /sec / 5sec = 1.2 cm/sec^2
???? I believe this is correct?
@& If the final velocity was 6 cm/s that would be correct.
If you get the correct final velocity you will find that this answer is easy to correct.*@
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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):
The graph would start at (0, 0) since the initial is 0. Then it would increase to the velocity of 6 cm/ sec. The graph would be positive with it increasing.
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It took about 35 minutes.
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@& Very close. You're doing a good job here.*@
&#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. &#