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: ->->->->->->->->->->->-> :
vAve= 20cm/2s = 10cm/s
vf= 10m/s * 2 - 0m/s= 20m/s
a= 20m/s / 2s= 10m/s^2
#$&*
• If the time interval is in error so that it is 3% longer than the actual time interval, then what are the actual values of the final velocity and acceleration?
answer/question/discussion: ->->->->->->->->->->->-> :
2= x+.03x so 2 = 1.03x so x= 1.94s
vf= 10.31m/s * 2 - 0m/s = 20.62 m/s
a= 20.62 m/s / 1.94s= 10.63 m/s^2
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• What is the percent error in each?
answer/question/discussion: ->->->->->->->->->->->-> :
vf percent error = (20.62- 20)/ 20.62 *100= 3%
a percent error =(10.63-10) / 10.63 *100= 6%
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• If the percent error is the same for both velocity and acceleration, explain why this must be so.
answer/question/discussion: ->->->->->->->->->->->-> :
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• If the percent errors are different explain why it must be so.
answer/question/discussion: ->->->->->->->->->->->-> :
the percent error for acceleration would be different than for final velocity because acceleration is dependent upon the number used in calculating final velocity. Since the time interval changed to 1.94s that also changed the final velocity which in turn changed the `dv. The `dv was then used to calculate acceleration so because in the acceleration formula more variable were changed than in the other equations, the percent errors differ.
Good. The bottom line is that `dt was used twice in the process, and contributed 3% to the error each time.
#$&*
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1 hour
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Good. See my note and check out the discussion; no revision is necessary.
&#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
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