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Phy 201
Your 'cq_1_09.1' 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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A ball accelerates uniformly as it rolls 20 cm down a ramp, starting from rest, in 2 seconds.
• What are its average velocity, final velocity and acceleration?
answer/question/discussion: ->->->->->->->->->->->-> :
vAve = 20 cm/s / 2 s = 10 cm/s
vf = 2 * 10 cm/s – 0 cm/s = 20 cm/s
aAve = 20 cm/s – 0 cm/s / 2 s = 10 cm/s^2
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• If the time interval is in error so that it is 3% longer than the actual time interval, then what are the actual values of the final velocity and acceleration?
answer/question/discussion: ->->->->->->->->->->->-> :
2 = + 3% error = actual time of 1.985 s (.03/2 = .015, 2 - .015 = 1.985s)
vf = 10.08 cm/s (20 cm/s / 1.985 s = 10.08 cm/s)
aAve = cm/s^2 ( 10.08 cm/s / 1.985 s = 5.08 cm/s^2)
`dv is not the same as v_Ave; you used v_Ave to calculate this acceleration.
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• What is the percent error in each?
answer/question/discussion: ->->->->->->->->->->->-> :
198 % error in vf ( 20 / 10.08 * 100%)
197 % error in aAve (10 / 5.08 * 100%)
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• If the percent error is the same for both velocity and acceleration, explain why this must be so.
answer/question/discussion: ->->->->->->->->->->->-> :
This would exemplify that there is constant acceleration or uniform motion as both yield same percentage of error.
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• If the percent errors are different explain why it must be so.
answer/question/discussion: ->->->->->->->->->->->-> :
Then this would be justified by the object not moving down at a uniform rate, the rate of change would be not equivalent due to variables.
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30 minutes
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9/29 1:30pm
You made just one error, but it affected all but your first answer. You should be able to revise this pretty quickly. See my note.
&#See any notes I might have inserted into your document. If there are no notes, this does not mean that your solution is completely correct.
Then please compare your solutions with the expanded discussion at the link
Solution
Self-critique your solutions, if this is necessary, according to the usual criteria. Insert any revisions, questions, etc. into a copy of this posted document. Mark any insertions with &&&& so they can be easily identified.If your solution is completely consistent with the given solution, you need do nothing further with this problem. &#