## 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.