Nothing Special   »   [go: up one dir, main page]

Mass of A Simple Pendulum: Small-Angle Approximation

Download as docx, pdf, or txt
Download as docx, pdf, or txt
You are on page 1of 2

SHM

Mass of a simple pendulum[edit]

The motion of an undampedpendulumapproximates to simple harmonic motion if the angle of oscillation is


small.

In the small-angle approximation, the motion of a simple pendulum is approximated by simple


harmonic motion. The period of a mass attached to a pendulum of length with gravitational
acceleration g is given by

This shows that the period of oscillation is independent of the amplitude and mass of the
pendulum but not of the acceleration due to gravity (g), therefore a pendulum of the same
length on the Moon would swing more slowly due to the Moon's lower gravitational field
strength.
This approximation is accurate only for small angles because of the expression for angular
acceleration being proportional to the sine of the displacement angle:

where

is the moment of inertia. When is small, sin and therefore the expression

becomes

SHM

which makes angular acceleration directly proportional to , satisfying the definition


of simple harmonic motion.

You might also like