The Intensity I of Light Varies Inversely as the Square $1 \frac { 2 } { 9 }$

question 69

Multiple Choice

The intensity I of light varies inversely as the square of the distance D from the source. If the intensity of illumination on a screen 5 ft from a light is 2 foot candles, find the intensity on a screen 15 ft from the light.

• A) \(1 \frac { 2 } { 9 }\) foot-candles
• B) \(\frac { 2 } { 9 }\) foot-candle
• C) \(\frac { 1 } { 5 }\) foot-candle
• D) 2 foot-candles