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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.
** CQ_1_03.1_labelMessages.txt **
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25 minutes
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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 ball goes from 0 to 5 sec down a ramp of 30 cm. The average velocity is (30 cm/5 seconds)= 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): Average of Initial velocity and average final velocity is equal to the average velocity.
Avg Velocity= 6 cm/sec
Initial Velocity=0 cm/sec
6cm/sec=(Vf+ 0 cm/sec)/2
Vf=12 cm/sec
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• By how much did its velocity therefore change?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line): The velocity changed from the initial velocity, it went from 0 cm/sec to 12 cm/sec. (12 cm/sec=0 cm/sec=12 cm/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): average rate= (change in velocity)/(clock time)
(12cm/sec)/(5 seconds)= 2.5 cm/sec^2
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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 have the clock time on the x-axis and the velocity on the y-axis. The rise is represented from the velocity (30 cm/sec), and the run is from the time (5 seconds). The slope represents the acceleration (rise/run=slope).
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The velocity never approaches 30 cm/s.
Can you revise your description of the graph?
&#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).
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