Question

Two points P₁ and P₂, are at distances of 4.0 m and 8.0 m, respectively, from a point

light source, S. if the intensity of light at P₁ is 24 W/m², the intensity of light at P2 is
closest to which of the following?
A. 6.0 W/m²
B. 12 W/m²
C 18 W/m²

Answer 1

6 W/m^2

Step-by-step explanation:

I= Power/4πr^2 so intensity of light is in inverse relationship with r^2 so the difference between P1 and P2 will be by four folds so P1 = 4*P2 or P1/4=P2 so 24/4= 6