SOLUTION: The intensity (I) of light from a light bulb varies inversely as the square of the distance (d) from the light bulb. Suppose (I) is 640 w/m^2 when the distance is 4m. How much furt

Algebra ->  Customizable Word Problem Solvers  -> Misc -> SOLUTION: The intensity (I) of light from a light bulb varies inversely as the square of the distance (d) from the light bulb. Suppose (I) is 640 w/m^2 when the distance is 4m. How much furt      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 337204: The intensity (I) of light from a light bulb varies inversely as the square of the distance (d) from the light bulb. Suppose (I) is 640 w/m^2 when the distance is 4m. How much further would it be to a point where the intensity is 250 w/m^2?
I have no idea what to do
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
No idea at all?
.
.
.
The intensity (I) of light from a light bulb varies inversely as the square of the distance (d) from the light bulb.
I=k%2Fd%5E2
640=k%2F%284%29%5E2
Solve for k.
Now you have k, find d2 when I=250.
Then find the difference between d2 and 4 m.
d=d2-4