 The period of a mass attached to a pendulum of length with gravitational acceleration formula_23 is given by

This shows that the period of oscillation is independent of the amplitude and mass of the pendulum but not of the acceleration due to gravity, formula_23, therefore a pendulum of the same length on the Moon would swing more slowly due to the Moon's lower gravitational field strength.Because the value of formula_23 varies slightly over the surface of the earth, the time period will vary slightly from place to place and will also vary with height above sea level.This approximation is accurate only for small angles because of the expression for angular acceleration being proportional to the sine of the displacement angle