cq_1_91

Your 'cq_1_9.1' report has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.

** **

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?

vAve = `ds/`dt = 20cm / 2s = 10cm/s

vf = 2vAve - v0 = 2(10) - 0 = 20cm/s

a = `dv/`dt = vf - v0/2 = 20 - 0/2 = 10cm/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?

actual time: 3 = 2 - t/t * 100

.03 = 2 - t/t

.03t = 2-t

.03t + t = 2

t(.03+1) = 2

t = 1.94175s

vAve = `ds/`dt = 20cm/1.94175s = 10.3cm/s

vf = 2vAve - v0 = 2(10.3) - 0 = 20.6cm/s

a = 20.6 - 0/1.94175 = 10.6cm/s^2

What is the percent error in each?

vAVe = abs.val. * [10 - 10.3/10.3] * 100 = 2.91% = 3%

vf = [20 - 20.6/20.6] * 100 = 2.91% = 3%

a = 5.66 = 6%

If the percent error is the same for both velocity and acceleration, explain why this must be so.

The percent error is not the same for both velocity & acceleration.

If the percent errors are different explain why it must be so.

The percent errors are different because the error in the time interval is magnified when carried through equations for velocity to the acceleration determination.

** **

20min.

** **

Please respond relative to goal of C.

************* This note is added to each submission to ensure that the instructor has reviewed your work. The instructor must manually remove this note. If it hasn't been removed, and if the instructor has not made specific responses, then it is possible that your work hasn't been properly reviewed and you should notify the instructor to be sure.

Your responses have been reviewed and everything looks good.

Please let me know if you have any questions related to this orientation assignment.