Pendulums

Science

Definition

A pendulum is a weight (bob) suspended from a pivot that swings back and forth under the influence of gravity. For small angles, it exhibits simple harmonic motion with a period that depends only on the length of the string and the acceleration due to gravity, not the mass or amplitude.

Examples

  • A grandfather clock using a pendulum to keep time
  • Foucault's pendulum demonstrating Earth's rotation
  • A wrecking ball swinging as a large-scale pendulum
Key Fact

T = 2π√(L/g), where L is length and g is gravitational acceleration.

Related Terms

Oscillation period Restoring force Springs Conservation of energy

Study This Concept

Practice pendulums with free review games in these units:

AP Physics 1 Unit 6: Simple Harmonic Motion