SOLUTION: the illumination produced by a light source depends on the distance from the source. For a particular light source, this relationship can be expressed as i=(4050)/(d^2), where i is

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equation Customizable Word Problems -> SOLUTION: the illumination produced by a light source depends on the distance from the source. For a particular light source, this relationship can be expressed as i=(4050)/(d^2), where i is      Log On


   

Question 547048: the illumination produced by a light source depends on the distance from the source. For a particular light source, this relationship can be expressed as i=(4050)/(d^2), where i is the amount of illumination in footcandles and d is the distance from the light (in feet). How far from the source is the illumination equal to 50 footcandles?
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
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he illumination produced by a light source depends on the distance from the source.
For a particular light source, this relationship can be expressed as i=(4050)/(d^2), where
i is the amount of illumination in footcandles and
d is the distance from the light (in feet).
How far from the source is the illumination equal to 50 footcandles?
:
50 = 4050%2Fd%5E2
multiply both sides by d^2
50d^2 = 4050
divide both sides by 50
d^2 = 4050%2F50
d^2 = 81
d = sqrt%2881%29
d = 9 ft