Question

A frequency generator (a device that produces sinusoidal signals whose frequency and amplitude can be independently set) is used to power a horn. The frequency is set to 2000 Hz, and for a particular amplitude the sound intensity is measured to be 0.030 W/m2 at a distance of 14 m. What is the power output of the horn in this case?

Answer 1

Answer:

73.9 W

Explanation

The sound intensity, I of the horn is given by I = P/A where P = Power output and A = area. Since this is a spherical wave, A = 4πr² where r = distance = 14 m. I = 0.030 W/m². So the power output, P = IA = 0.030 × 4π × 14² = 73.89 W ≅ 73.9 W