Don't forget to measure from the normal. Light leaves a diamond and enters water. Given the angle shown, calculate q. 18. Find the angle at which light leaves the prism. Light passes through a block of glass with parallel sides.
Light enters the prism shown, and reflects off a silvered side.
The path of every light ray could be reversed. In other words, the path of a light ray will be the same whether it is going forward or backward. Obviously it can't skim the surface afater it exits, that would be duplicating a path already called for. The angle at which this reflection occurs is called the critical angle . Find the critical angle for water.