Intensity: Observer A is 3.0 m from a tiny light bulb and observer B is 12.0 m from the same bulb. Assume that the light spreads out uniformly and undergoes no significant reflections or absorption. If observer B sees a light of intensity I, the light intensity that A sees is
A) I.
B) 9I.
C) 16I.
D) 36I.
E) 144I.

Question

Quizplus · Accepted Answer

The intensity of light is inversely proportional to the square of the distance from the source. So, the intensity of light that A sees is 16 times the intensity of light that B sees.

Intensity: Observer a Is 3