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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.
** CQ_1_09.1_labelMessages **
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=20cm/2s=10cm/s
10cm/s=(vf+0)/2
20cm/s=vf
a=(20cm/s-0cm/s)/2s=10cm/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: ->->->->->->->->->->->-> :
20cm/2.06s=9.71cm/s
9.71cm/s=(vf+0)/2
19.42cm/s=vf
a=(19.42-0)/2.06s=9.43cm/s^2
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What is the percent error in each?
answer/question/discussion: ->->->->->->->->->->->-> :
(10-9.71)/10=2.9%
(20-19.42)/20=2.9%
(10-9.43)/10=5.7%
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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: ->->->->->->->->->->->-> :
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If the percent errors are different explain why it must be so.
answer/question/discussion: ->->->->->->->->->->->-> :
The acceleration is doubled since the 2s is used with the 3%error
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*#&!
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In finding the acceleration you divide twice by `dt, adding a 3% error each time and ending up with pretty much a 6% error.
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