Assuming that the wave speed varies little when sound waves are traveling through a material that suddenly changes density by 10%,what percentage of the incident wave intensity is reflected?
A)

Question

Assuming that the wave speed varies little when sound waves are traveling through a material that suddenly changes density by 10%,what percentage of the incident wave intensity is reflected?
A)< 1%
B)7.0%
C)10%
D)20%
E)25%

Quizplus · Accepted Answer

When the wave speed is approximately constant, the reflection coefficient for intensity is given by the formula R = ((Z2 - Z1)/(Z2 + Z1))^2, where Z is the acoustic impedance. For a small change in density, the reflection coefficient is very small, resulting in less than 1% of the intensity being reflected.

Assuming That the Wave Speed Varies Little When Sound Waves