Question

How many times as bright as a light that is 90 m away from you does a light that is 10 m away from you appear?

Answer 1

Answer:

81 x as bright

Explanation:

The intensity of light is dependent on distance according to this simple equation:

(90/10)^2 = 9^2

                = 81

This was derived from the inverse-square law. Respectively a light that is 10 m away from you is 81 x as bright.