cq_1_031

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):

vAve = 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):

final velocity = 2 * vAve - initial velocity

final velocity = 2 * 6 cm/s - 0 = 12 cm/s

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• By how much did its velocity therefore change?

answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):

The change in velocity is 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):

a = (12 cm/s - 0) / 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 have a horizontal axis representing time from 0 seconds to at least 5 seconds. The vertical axis would represent velocity from 0 to at least 12 cm/s. The graph would be a straight line that would start at the (0, 0) coordinates through (5, 12) coordinates.

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30 min

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&#Very good responses. Let me know if you have questions. &#