# Math - Logorithms

posted by .

The intensity, I, of light, in lumens, passing through the glass of a pair of sunglasses if given by the equation I(x) = I^o(0.8)^x, where x is the thickness of the glass, in millimeters, and I^o is the intensity of light entering the glasses. How thick should the glass be so that it will block 25% of the light entering the sunglasses?

• Math - Logorithms -

We want

I^o(.25) = I^o(.8)^x
.25 = .8^x
ln.25 = x*ln.8
x = ln.25/ln.8 = 6.21

## Similar Questions

1. ### Physics

When light travels from air to glass, which one of the following is not dependent on the index of refraction of the glass?
2. ### Science

Which of these statements concerning the interaction of light waves with the glass of a greenhouse is correct?
3. ### Calculus

Light is absorbed when it passes through a glass window. If r% of light is absorbed by a glass with thickness w , then the percent of light that is absorbed by a piece of glass with a thickness nw of for any natural number n is modeled …
4. ### Calculus

Light is absorbed when it passes through a glass window. If r% of light is absorbed by a glass with thickness w , then the percent of light that is absorbed by a piece of glass with a thickness nw of for any natural number n is modeled …
5. ### Calculus

Light is absorbed when it passes through a glass window. If r% of light is absorbed by a glass with thickness w , then the percent of light that is absorbed by a piece of glass with a thickness nw of for any natural number n is modeled …
6. ### Calculus

Light is absorbed when it passes through a glass window. If r% of light is absorbed by a glass with thickness w , then the percent of light that is absorbed by a piece of glass with a thickness nw of for any natural number n is modeled …
7. ### Calculus

Light is absorbed when it passes through a glass window. If r% of light is absorbed by a glass with thickness w , then the percent of light that is absorbed by a piece of glass with a thickness nw of for any natural number n is modeled …
8. ### Calculus

Question : Light is absorbed when it passes through a glass window. If r % of light is absorbed by a glass with thickness w, then the percent of light that is absorbed by a piece of glass with a thickness of nw for any natural number …
9. ### algebra worksheet help please

Fiber-optic cables are used widely for Internet wiring, data transmission, and surgeries. When light passes through a fiber-optic cable, its intensity decreases with the increase in the length of the cable. If 1,500 lumens of light …
10. ### science sound and light!!!

which of the following involves the diffraction of light waves?

More Similar Questions