course Phy 231
June 196:45 pm
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?
It's average velocity is 10 cm/s. It's final velocity is 20 cm/s, and it's acceleration is 10cm/s^2.
answer/question/discussion:
• 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?
The actual time interval would be 2.06 seconds. Its final velocity would be 19.4 cm/s and its acceleration would be 9.71 m/s^2.
answer/question/discussion:
• What is the percent error in each?
The error in final velocity would be 3% and the error in acceleration would also be 3%.
answer/question/discussion:
• If the percent error is the same for both velocity and acceleration, explain why this must be so.
Since time, velocity, and acceleration are all proportional when there is uniform acceleration, a % error in one of the values will lead to the same % error in the other values.
answer/question/discussion:
• If the percent errors are different explain why it must be so.
If the percent errors are different, this would be because the acceleration is not uniform, therefore the values will not be proportional.
answer/question/discussion:
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