SOLUTION: The intensity, I, of light received from a source varies inversely as the square of the distance, d, from the source. If the light intensity is 2 foot-candles at 11 feet, find the

Algebra ->  Customizable Word Problem Solvers  -> Misc -> SOLUTION: The intensity, I, of light received from a source varies inversely as the square of the distance, d, from the source. If the light intensity is 2 foot-candles at 11 feet, find the      Log On

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Question 37723: The intensity, I, of light received from a source varies inversely as the square of the distance, d, from the source. If the light intensity is 2 foot-candles at 11 feet, find the light intensity at 19 feet. Round your answer to the nearest hundredth if necessary.
Answer by fractalier(6550) About Me  (Show Source):
You can put this solution on YOUR website!
We express this relationship as
I = k/d^2
Plug in to find k
k = Id^2 = 2(11^2) = 242
Now find I for this k and a different d...
I = k/d^2 = 242/19^2 = 242/361
I = .67 foot-candles