How the change of amplitude effects the time of one cycle of a pendulum?
Denote the length of the pendulum by L and the amplitude by A. The period is given by:
T = 2 pi sqrt(L/g) [1 + 1/16 (A/L)^2 + term of order (A/L)^4]
T = 2 pi sqrt(L/g) [1 + 1/16 (A/L)^2 + term of order (A/L)^4]