Question

A flying hawk makes a noise of frequency 50 Hz that spreads evenly in every direction. The intensity at the ground, 60 m below, is measured at 70 dB. What is the power radiated by the hawk?

Answer 1

The power radiated by the hawk is 0.452 Watt.

Step-by-step explanation:

Given that,

Frequency = 50 Hz

Distance r=60 m

Level = 70 dB

We need to calculate the intensity

Using formula of intensity

`dB=10 log((I)/(I_(0)))`

Put the value into the formula

`70=10 log((I)/(10^(-12)))`

`I=10^(7)*10^(-12)`

`I = 1*10^(-5)\ W/m^2`

We need to calculate the power radiated by the hawk

Using formula of power

`P = I* 4\pi r^2`

Put the value into the formula

`P=1*10^(-5)*4\pi*(60)^2`

`P=0.452\ W`

Hence, The power radiated by the hawk is 0.452 Watt.