cq_1_051

Phy 201

Your 'cq_1_05.1' 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 accelerates at 8 cm/s^2 for 3 seconds, starting with velocity 12 cm/s.

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What will be its velocity after the 3 seconds has elapsed?

answer/question/discussion: v = vo + at = 12 cm/s + 8 cm/s^2 * 3 s = 24 cm/s^2 + 12 cm/s = 36 cm/s

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Assuming that acceleration is constant, what will be its average velocity during this interval?

answer/question/discussion: vAve = (36 cm/s - 12 cm/s) / 3 s = 8 cm/s

Your calculation would represent the average acceleration, not the average velocity. The units of the calculation you indicate here would be cm/s^2, not the cm/s you report.

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How far will it travel during this interval?

answer/question/discussion: If for every 1 second the change is 8 cm, then the distance should be 8 cm * 3 = 24 cm

8 cm * 3 s = 24 cm * s, not 24 m.

There is in any case no quantity in this problem which is equal to 8 cm/s (see my previous note).

You would use the average velocity to get this result, but you would have to use the correct average velocity and be very careful to express the entire calculation in the correct units.

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8 minutes

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Most of your work is correct, and most of the incorrect work isn't far wrong.

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