SOLUTION: the intensity of light, l, received at a source varies inversely as the square of the the distance, d, from the source. if the light intensity is 79 foot-candles at 30 feet, find t
Algebra.Com
Question 666455: the intensity of light, l, received at a source varies inversely as the square of the the distance, d, from the source. if the light intensity is 79 foot-candles at 30 feet, find the light intensity at 10 feet
Answer by DrBeeee(684) (Show Source): You can put this solution on YOUR website!
Use
(1) I = c/(d^2), where I is the intensity in foot-candles, c a constant of propotionality and d is the distance in feet.
First we find c using the known intensity at a known distance or
(2) I = c/30^2 = 79, giving
(3) c = 79*900
To find the intensity at 10 feet use (1) with c of (3) and get
(4) I at 10' = 79*900/10^2 or
(5) I at 10' = 79*9 = 711
Answer: The light intensity at 10' is 711 foot-candles.
RELATED QUESTIONS
The intensity 1, of light received from a source varies inversely as the square of the... (answered by josgarithmetic)
The intensity of light received from a source varies inversely as the square of the... (answered by Fombitz)
The intensity of a light varies inversely as the square of the distance from the light... (answered by ewatrrr)
The intensity, I, of light received from a source varies inversely as the square of the... (answered by fractalier)
The intensity, I, of light received at a source varies inversely as the square of... (answered by jorel1380)
The intensity, I, of light received fro a source varies inversely as the square of the... (answered by josgarithmetic)
The intensity of light varies inversely a the square of the distance from the light... (answered by stanbon)
The intensity of light varies inversely as the square of the distance from the light... (answered by Alan3354)
The intensity of a light source varies inversely as the square of the distance from the... (answered by devjyotsingh24)