Anonymous
Anonymous asked in Science & MathematicsPhysics · 9 years ago

# Trouble understanding snell's law?

I'm doing a science fair project using snell's law and I don't understand what exactly it is...can you explain to me in a ninth grade vocabulary? Thnx :)

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• Jason
Lv 4
9 years ago

Snell's Law is about the movement of light through different materials. You know how a prism bends light? Well that's because light moves differently through glass than it does through air. If it didn't, you'd be walking into glass doors all the time because it wouldn't look any different than the air around it!

So Snell's law is about determining how much the light will bend, or "refract" when it passes through a new surface. It depends on how steep of an angle the light approaches the surface, and it also depends on a property called the "index of refraction" which is characteristic to the material. For example, the index of refraction for air is 1, and for water is 1.33. Using some basic trig, you can tell how much the light will refract.

It's important to understand how the light will refract for things like making lenses. Eyeglasses, microscopes, magnifying glasses, all work by manipulating the light to approach our eyes differently so that we can focus on something that would have been difficult to see before.

• Doug J
Lv 4
9 years ago

Snell's law states that the ratio of the sines of the angles of incidence and refraction is equivalent to the ratio of phase velocities in the two media, or equivalent to the opposite ratio of the indices of refraction:

If two surfaces of different material are put next to each other such as water and glass, snells law can be used to calculate the angle light will refract through the second medium given you know the angle it is coming through the first material.

This link shows a picture of the angles.

http://en.wikipedia.org/wiki/Snell's_law