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: ->->->->->->->->->->->-> :
30 cm/5 sec= 6 cm/s/s
• 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: ->->->->->->->->->->->-> :
12 cm/s/s
• By how much did its velocity therefore change?
answer/question/discussion: ->->->->->->->->->->->-> :
12cm/s/s-6cm/s/s= 6 cm/s/s
this is final velocity - average velocity, which is not change in velocity
• At what average rate did its velocity change with respect to clock time?
answer/question/discussion: ->->->->->->->->->->->-> :
(12cm/s)/(5s)= 2.4 cm/s/s
good
What would a graph of its velocity vs. clock time look like? Give the best description you can.
answer/question/discussion: ->->->->->->->->->->->-> :
The graph would have an upward curve going in the positive direction.
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30 minutes
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I'm a little confused about the final and initial velocity. For the final velocity do you just double the average velocity? I'm still not sure how to get the initial velocity unless it is given to me in the problem.
The given problem states
'A ball starts with velocity 0 ...'
This tells you the initial velocity.
You did pretty well here, but had one error, which I noted. Be sure you understand everything at the link:
&#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. &#