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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: ->->->->->->->->->->->-> :
v_ave = ‘ds/’dt = 20 cm / 2 s = 10 cm/s
Since v_0 = 0, v_f = v_ave*2 = 20 cm/s and ‘dv = 20 cm/s
A=’dv/’dt = 20 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: ->->->->->->->->->->->-> :
Then ‘dt would be 2 * 1.03 = 2.06 s
V_ave = 20 cm / 2.06 s = 9.71 cm/s
V_f would be 9.71 * 2 = 19.42 cm/s
A = 19.42 cm/s / 2.06 s = 9.43 cm/s^2
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• What is the percent error in each?
answer/question/discussion: ->->->->->->->->->->->-> :
% error v_f = 0.58 / 20 *100 = 2.9%
% error a = 0.57 / 10 * 100 = 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 percent is different because the units in velocity account for ‘dt only once in the denominator and a accounts for ‘dt twice in the denominator.
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10 min.
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&#Very good responses. Let me know if you have questions. &#