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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.
** 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):
vAve = 'ds / 'dt = 30 cm / 5 s = 6 cm / s
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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):
vFinal = 2 * vAve = 2 * 6 cm/s = 12 cm/s
When a uniformly accelerating object is observed over a time interval in which it starts from rest, and only when it starts from rest, its average velocity will be half of its final velocity
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• By how much did its velocity therefore change?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
'dv = 12 cm/s - 0 cm/s = 12 cm/s
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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):
acceleration = change in velocity divided by the time interval = 'dv / 'dt = (12 cm/s - 0 cm/s) / 5 s = 12 cm/s / 5 s = 2.4 cm/s^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 be linear. There would be a straight line increasing from left to right. The data points would be:
0 0
1 2.4
2 4.8
3 7.2
4 9.6
5 12
The first column represents time in seconds and the second column represents velocity in cm/s.
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15
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&#Very good responses. Let me know if you have questions. &#