A light bulb produces 23 W of power emitted uniformly in all

A light bulb produces 23 W of power, emitted uniformly in all directions. Find the average intensity at the following.

(a) at a distance of 4.30 m from the bulb. (in mW/m2)

(b) at a distance of 23.5 m from the bulb. (in mW/m2)

P = 23 W

a) intensity = P/(4pi * d^2)

intensity = 23/(4pi * 4.3^2)

intensity = 0.099 W/m^2

intensity = 99 mW/m^2

b) at d = 23.5 m

intensity = P/(4pi * d^2)

intensity = 23/(4pi * 23.5^2)

intensity = 0.00331 W/m^2

Intensity = 3.31 mW/m^2