Energy and Power of a Wave

14.4 Energy and Power of a Wave
Learning Objectives
By the end of this section, you will be able to:
- Explain how energy travels with a pulse or wave
- Describe, using a mathematical expression, how the energy in a wave depends on the amplitude of the wave
Energy and Power in Waves


Discuss!

Three waves are traveling along identical strings. Wave B has twice the amplitude of the other two. Wave C has 1/2 the wavelength than A or B. Which wave, B or C, carries more energy per time (power)?
A sinusoidal wave on a string is described by the wave function:

where x and y are in meters and t is in seconds. The mass per unit length of this string is 12 g/m.
(a) Determine the speed of the wave.
(b) Determine the wavelength of the wave.
(c) Determine the frequency of the wave.
(d) Determine the power transmitted by the wave.