If the distance from a light source triples, how does light intensity change? The intensity will be 3x greater. The intensity will be 1/3 as much. The intensity will be 1/9 as m…

Question

asked May 11, 2020 183k views

1 Answer

Kevin Watson · Answer 1 · 2020-05-17T14:03:56+0000

Answer:

The intensity will be 1/9 as much.

Step-by-step explanation:

The intensity of the light or any source is inversely related to the square of the distance.

$I\alpha (1)/(r^(2) )$

Now according to the question the distance is increased by three times than,

(I_(2) )/(I_(1) )=(r_(1)^(2) )/(r_(2)^(2) )

Therefore,

$(I_(2) )/(I_(1) )=(r_(1)^(2) )/((3r_(1))^(2) )\\(I_(2) )/(I_(1) )=(1)/(9) \\{I_(2)=(1)/(9){I_(1) }$

Therefore the intensity will become 1/9 times to the initial intensity.