Question

The intensity I of light bulb measured in watts per square meter (w/m^2), varies inversely as the square of the distance d from the light bulb . . suppose I is 45 w/m^2 when the distance is 5 m . find the intensity when the distance from the light bulb is 7 m away

Answer 1

"The intensity I of light bulb...varies inversely as the square of the distance d from the light bulb"

so

I = k/(d^2)

Answer 2

Plug in I = 45 and d = 5

I = k/(d^2)

45 = k/(5^2)

k = ???

Answer 3

would it be 1125/49

Answer 4

i figured it over hours of trying

Answer 5

that is correct

Answer 6

I = 1125/49 when d = 7

Answer 7

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