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PHY201
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: ->->->->->->->->->->->-> :
20/2=10 =vAve
v0=10
since it is uniform would it still not be 10cm/s for vf?
'starts from rest' means initial velocity is zero
velocity isn't uniform, acceleration is
'ds=v0'dt+.5a'dt
20=10(2) + .5a(2)
20=20+.5a2
0=a
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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: ->->->->->->->->->->->-> :
vf=13cm/s
vf=v0+a'dt
13=10+a(2)
3=2a
a=3/2= 1.5cm/s^2
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What is the percent error in each?
answer/question/discussion: ->->->->->->->->->->->-> :
3% error
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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: ->->->->->->->->->->->-> :
Since we are using uniform velocity if it is 3% error then everything would be off by 3%.
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If the percent errors are different explain why it must be so.
answer/question/discussion: ->->->->->->->->->->->-> :
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10 minutes
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You need to revise this one. It's uniform acceleration, not uniform velocity; that got you off on the wrong foot at the beginning.
&#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. &#