Physics Hall · EXH-0006

What makes a pendulum swing faster?

A playground swing and a clock pendulum repeat their motion, but not always at the same pace.

What should you look for?

What changed the pace?

For a simple pendulum at small angles, period grows with the square root of string length.

A heavier bob feels more gravitational force but also has more inertia, so mass does not appear in the ideal period formula.

The animation uses the small-angle period. Large angles, air drag, and a massive string are simplified.

Change length, mass, and release angle. Compare mode keeps a second pendulum beside the first.

Science source