Question

A laser is aimed at the top of a pool of water. The beam makes an angle of 32 degrees to the normal to the water's surface. If the pool of water is 2.3 m deep with a flat bottom, where will the light beam hit the bottom of the pool relative to its entrance point on the air–water interface. Use nair = 1 and nwater = 1.33 for your calculations.

Answer 1

Using Snell's Law, we can calculate the the angle the light beam makes with the normal

The beam will hit the bottom of the pool some distance away. The tangent of this angle will be equal to the ratio of this distance and the depth of the pool.

The beam will hit the floor a horizontal distance of and a vertical distance of away.