# The Intensity I, of light received at a source varies inversely as the square of the distance,d,from the source, If the intensity if 53 foot-candles at 45 feet, find the intensity at 9 feet?

Apr 21, 2017

$= 1325$ foot-candles

#### Explanation:

Intensity at $9 f e e t = {\left(\frac{45}{9}\right)}^{2} \times 53$

$= {\left(5\right)}^{2} \times 53$

$= 25 \times 53$

$= 1325$