How the change of amplitude effects the time of one cycle of a pendulum?

2 answers

Thank you for using the Jiskha Homework Help Forum. Try the following about a pendulum:

www.explorelearning.com/View/documents/EG_Pendulum2.pdf

(PDF file to download)
Denote the length of the pendulum by L and the amplitude by A. The period (time of one cycle) is given by:

T = 2 pi sqrt(L/g) [1 + 1/16 (A/L)^2 + term of order (A/L)^4]

So, increasing the amplitude will make the period longer. The effect is proportional to (A/L)^2 and thus becomes very small if the length is much larger than the amplitude.