# Simple Harmonic Motion

AQA A - Simple Harmonic Motion

- Created by: Amy
- Created on: 03-01-13 12:55

First 235 words of the document:

PHY4A

Simple Harmonic motion

Conditions

A body will oscillate with simple harmonic motion if the resorting force acting on it (pulling the body

back towards a rest position) is directly proportional to the body's displacement. A restoring force

results in an acceleration which is in the opposite direction to the body's displacement.

The conditions for simple harmonic motion are summarized by:

a x

Where a is acceleration and x is displacement. The minus sign shows that the acceleration is in the

opposite direction to the displacement vector.

Simple harmonic motion and circular motion

An object on a turntable rotating with constant speed will have a constant angular velocity, . When

viewed from the side the object moves in a straight line with simple harmonic motion where:

= 2/T = 2f

T is the time for one oscillation and f is the frequency or number of oscillations per second.

Phase and phase difference

Different points on the rim of a spinning wheel are said to be out of step out of phase. The phase

difference between any 2 points is the angle between them. When the term phase is applied to

waves and oscillations more generally, one complete oscillation is taken to be equivalent to one

rotation or 2 radians and phase differences are measured in radians.

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