Homework Help: math

Posted by Suzie on Friday, February 24, 2012 at 5:47pm.

after passing therough a material t centimeters thick, the intensity I(t) of a light beam is given by I(t) =(4^-ct)Io, where Io is the initial intensity and c is a constant called the absorption factor. Ocean water absorbs light with an absorption factor of c= .0101. at what depth will a beam of light be reduced to 50% of its initial intensity? 2% of its initial intensity?

math - Reiny, Friday, February 24, 2012 at 7:24pm
I will do the last part
to have only 2% of the intensity left,
l(t) = .02

.02 = 4^(-.0101t) (1)
ln .02 = -.0101t ln4
-.0101t = ln .02 /ln4 = -2.821928
t = -2.821928/-.0101 = 279.4

for the 50% question , set the left side equal to .5

Answer this Question

Related Questions

Math - Logorithms - The intensity, I, of light, in lumens, passing through the ...
physics - By what length is a light ray displaced after passing through a 4.7 cm...
physics - By what length is a light ray displaced after passing through a 4.7 cm...
physics - A beam of light makes an angle of 13.0° with the normal of a ...
physics - Linearly polarized light is incident on a piece of polarizing material...
physics - The angle between the polarizer transmission axis and the plane of ...
Geometric & Wave Optics - A beam of light wavelenght 560 to availing in air ...
Math - The strength S of a rectangular beam varies jointly as its width w and ...
Physics - We want to rotate the direction of polarization of a beam of polarized...
Physics - We want to rotate the direction of polarization of a beam of polarized...

For Further Reading

First Name:
School Subject:
Answer: