Simple Pendulum
Definition
A mass hanging from a string or rod that swings back and forth — the classic example of periodic motion.
Symbol: · Unit: s (period)
Technical definition
An idealized pendulum: point mass m on a massless string of length L, small angular amplitude. Its period is T = 2π√(L/g), independent of mass and (for small angles) amplitude — the basis of pendulum clocks.
Example
A 1-meter pendulum has a period of about 2.0 seconds — which is why ‘seconds pendulums’ (~0.994 m) were used in precision clocks.
Common confusion
The period does NOT depend on the bob's mass or how far you pull it (for small angles). Heavier bobs and wider small swings take the same time — only the string length and gravity matter.