Question

A pendulum is timed, first for 20 swings and then for

50 swings:
time for 20 swings = 17.4s
time for 50 swings = 43.2 s
Calculate the average time per swing in each case.
The answers are slightly different. Can you suggest
any experimental reasons for this?

Answer 1

`w = (t(50) - t(20))/(50 - 20) = (43.2 - 17.4)/(50 - 20)`

`w = (25.8)/(30) = 0.86 \: sec \: per \: swing`

The results may differ due to resistive forces that may be affecting the system by decelerating it or any other external forces that might accelerate it a bit.Or the timing could be a little inaccurate.