Question

A typical adult ear has a surface area of 2.90 × 10-3 m2. The sound intensity during a normal conversation is about 2.19 × 10-6 W/m2 at the listener's ear. Assume that the sound strikes the surface of the ear perpendicularly. How much power is intercepted by the ear?

Answer 1

`6.35\cdot 10^(-9) W`

Step-by-step explanation:

The relationship between power and intensity of a sound is given by:

`I=(P)/(A)`

where

I is the intensity

P is the power

A is the area considered

In this problem, we know

`A=2.90\cdot 10^(-3)m^2` is the surface area of the ear

`I = 2.19\cdot 10^(-6) W/m^2` is the intensity of the sound

Re-arranging the equation, we can find the power intercepted by the ear:

`P=IA=(2.19\cdot 10^(-6) W/m^2)(2.90\cdot 10^(-3) m^2)=6.35\cdot 10^(-9) W`