Wave Motion in Physics
A wave carries energy without carrying matter. The particles of the string or the air only shuffle about their own resting places, while the disturbance itself keeps moving on, which is why a wave can cross an ocean without a single drop of water travelling the whole way. What travels is a shape, and that shape has three numbers tied together by one relation, speed, frequency and wavelength. The blocks give that relation and the wave functions built on it, the speed that a stretched string supports, which depends on tension and mass per unit length rather than on how hard you flick it, and the power such a wave carries.
Wave speed from the wavelength and the frequency
Given
- (m)
- (Hz)
Wavelength from the wave speed and the frequency
Given
- (m/s)
- (Hz)
Wave number from the wavelength
Given
- (m)
Angular frequency of a wave
Given
- (Hz)
- (s)
Wave travelling in the positive x direction
Given
- (m)
- (rad/m)
- (rad/s)
- (rad)
Wave travelling in the negative x direction
Given
- (m)
- (rad/m)
- (rad/s)
- (rad)
Linear mass density of a string
Given
- (kg)
- (m)
Speed of a wave on a stretched string
Given
- (N)
- (kg/m)
Tension needed for a given wave speed
Given
- (m/s)
- (kg/m)
Power carried by a sinusoidal wave on a string
Given
- (kg/m)
- (rad/s)
- (m)
- (m/s)
Intensity of a wave spreading from a point source
Given
- (W)
- (m)
The linear wave equation
Given
- (m/s)