A 1.2 W point source emits sound waves isotropically. Assuming that the energy of the waves is conserved, find the intensity (a)1.6 m from the source and (b)2.2 m from the source.

(a)

(b)

Explanation:

Given:

Point source

Distance from source Part a

Distance from source Part b

Solution:

Part (a)

Using intensity formula at distance L from an isotropic point.

 -------------------(1)

Substitute and in equation 1..

Part (b)

Substitute and in equation 1.

Therefore, the intensity at distance 1.6 m from the source:

.

And, the intensity at distance 2.2 m from the source:

.

a

explanation:

no diagram was provided, but i'm guessing it's the one i've attached to my answer.

here, a mechanical force turns the rod.   this generates an electric current in the coil, which powers the bulb.