## Quick Reference

Any rigid body that swings about a fixed point. The **ideal simple pendulum** consists of a bob of small mass oscillating back and forth through a small angle at the end of a string or wire of negligible mass. Such a device has a period 2π√(*l*/*g*), where *l* is the length of the string or wire and *g* is the acceleration of free fall. This type of pendulum moves with simple harmonic motion.

The **compound pendulum** consists of a rigid body swinging about a point within it. The period of such a pendulum is given by *T* = 2π√[(*h*^{2} + *k*^{2})/*hg*], where *k* is the radius of gyration about an axis through the centre of mass and *h* is the distance from the pivot to the centre of mass. See also Kater's pendulum.

**From:**
pendulum
in
A Dictionary of Physics »

*Subjects:*
Physics.

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