AQA A Level Physics复习笔记6.2.5 Period of Simple Pendulum

• A simple pendulum is another type of simple harmonic oscillator
  • The pendulum consists of a string and a bob (a weight, generally spherical) at the end

   

• The time period of a simple pendulum is given by:

• Where:
  • T = time period (s)
  • L = length of string (m)
  • g = gravitational field strength (N kg-1)

   

• Length L is taken from the pivot to the centre of mass of the bob
• Normally, the bob is taken as a point mass, so l is just the length of the string

A simple pendulum

• The time period of a pendulum does depend on the gravitational field strength, meaning its period would be different on the Earth and the Moon
• The limitation with this formula, and the conditions for which it applies one for small angles from the equilibrium point (~10°) (and therefore small amplitudes)