#$&*
Phy 201
Your 'cq_1_03.1' report has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.
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The problem:
A ball starts with velocity 0 and accelerates uniformly down a ramp of length 30 cm, covering the distance in 5 seconds.
• What is its average velocity?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
The average velocity is 6cm/sec.
Change in position / Change in time, 30cm / 5 seconds = 6 cm/sec
#$&*
• 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):
Therefore, the final velocity is 3cm/sec.
(0 + 6 = 6, 6/2 = 3)
@& 6 cm / sec is your average velocity.
(initial vel + ave vel) / 2 is not the final vel.
(initial vel + final vel) / 2 is the average vel.
What therefore must the final velocity be?*@
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• By how much did its velocity therefore change?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
The velocity changed by 3.
#$&*
@& If the initial and final velocities were 0 and 3 cm/s, then the change in velocity would be 3 cm/s.
However see my previous note.
Note that you also need to include units with any quantity that has units.*@
• At what average rate did its velocity change with respect to clock time?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
The velocity changed at an average rate of 10 cm/sec with respect to clock time.
#$&*
@& You don't say how you got this.
In any case you need to apply the definition of rate carefully, one step at a time, and indicate how you have reasoned out this result.*@
• 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):
Since the ball is uniformly accelerating with an increasing velocity, I believe the graph would be increasing at an increasing rate.
#$&*
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25 minutes
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@& Good attempt, but on some questions you need to reason out your answers in more detail.
See my notes.
&#Please see my notes and, unless my notes indicate that revision is optional, submit a copy of this document with revisions 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.
If my notes indicate that revision is optional, use your own judgement as to whether a revision will benefit you. &#
*@