# Compound pendulum ( ordinary frequency )

## Description

A compound pendulum is a body formed from an assembly of particles or continuous shapes that rotates rigidly around a pivot. Its moments of inertia is the sum the moments of inertia of each of the particles that is composed of.
Any swinging rigid body free to rotate about a fixed horizontal axis is called a compound pendulum or physical pendulum. The appropriate equivalent length L for calculating the period ( or ordinary frequency ) of any such pendulum is the distance from the pivot to the center of oscillation.

The natural frequency of a compound pendulum depends on its moment of inertia.

## Variables

π | pi |

f | The ordinary frequency (Hz) |

m | Mass of the object (kg) |

g | Local acceleration of gravity (m/s^{2}) |

r | Distance from the pivot point to the centre of mass of the object (m) |

I_{P} | Moment of inertia of the pendulum (kg*m^{2}) |