Question

Calculate the light intensity 1.45 m from a light bulb that radiates 100 W equally in all directions.

Answer 1

Answer:

I = 3.785 W/m²

Explanation:

given,

distance from the light, r = 1.45 m

Power of bulb = 100 W

The area is that of a sphere with a radius equal to the distance from the light bulb.

The formula for the area of a sphere of radius 1.45 meters is:

A = 4 π r²

A = 4 x π x 1.45²

A = 26.42 m²

Intensity of the light is equal to

$I = \dfrac{P}{A}$

$I = \dfrac{100}{26.42}$

      I = 3.785 W/m²

Intensity of the light at 1.45 m is equal to I = 3.785 W/m²