A body radiates energy at a rate (power) .

PHYSICS · Multi-part · A Level · Physics · Waves · Waves

Problem

A body radiates energy at a rate (power)

P

. (1) Deduce that the intensity of this radiation at distance

d

from the body is given by:

I = \frac{P}{4\pi d^2}

(2) State *one* assumption made in deriving this result.