A microphone of cross sectional area `0.80 cm^2`is placed in front of a small speaker emitting 3.0 W of sound output. If the distance between the microphone and the speaker is 2.0 m how much energy falls on the microphone in 5.0 s?

Explanation

To solve the problem, we need to determine how much energy falls on the microphone in 5 seconds given the power output of the speaker and the distance from the speaker to the microphone. Here’s a step-by-step solution:

### Step 1: Calculate the Surface Area of the Sphere
The sound from the speaker spreads out uniformly in all directions, creating a spherical wavefront. The surface area \( A_s \) of a sphere is given by the formula:
\[ A_s = 4 \pi r^2 \]
where \( r \) is the radius of the sphere (the distance from the speaker to the microphone).
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