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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= `ds/`dt = 20cm/2s = 10cm/s
`ds=v0*`dt+ ½*a*`dt^2
20cm= 0cm/s * 2s + ½*a*(2s)^2
20cm= ½*a*4s^2
40cm= a*4s^2
a= 10cm/s^2
vf= v0+a*`dt
vf= 0+ 10cm/s^2 *2s
vf= 20cm/s
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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: ->->->->->->->->->->->-> :
First we need to see what the actual time interval is so I calculated that:
1.03x= 2s
x=1.94s
20cm=1/2*a*(1.94s)^2
40cm= a*3.76s^2
a= 10.6cm/s^2
vf= 0+ 10.6cm/s^2 *1.94s = 20.6cm/s
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• What is the percent error in each?
answer/question/discussion: ->->->->->->->->->->->-> :
The percent error for vf is 0.03/20.6 *100 = 0.15%
The percent error for acceleration is 0.03/ 10.6 * 100 = 0.28%
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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: ->->->->->->->->->->->-> :
The percent errors are not the same.
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• If the percent errors are different explain why it must be so.
answer/question/discussion: ->->->->->->->->->->->-> :
The percent errors are different because it is a different proportion of the error over the estimate in each.
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30min
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@& Good work, but be sure to check the link. No need for a revision unless you have questions.*@
&#See any notes I might have inserted into your document, and before looking at the link below see if you can modify your solutions. If there are no notes, this does not mean that your solution is completely correct.
Then please compare your old and new solutions with the expanded discussion at the link
Solution
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