# Refraction.

## Presentation on theme: "Refraction."— Presentation transcript:

Refraction

Refraction The bending of light when it travels from one medium to another Ex.

Why does light Refract? The speed of light changes when light travels in a different medium Ex. Speed of light in a vacuum = 3.0 x 108 m/s Speed of light in water = 2.26 x 108 m/s When a beam of light enters a slower medium, the part of the beam that enters first will slow down first changing the direction of light (like a car traveling from pavement to sand)

Rules for Refraction 1. The incident ray, the refracted ray and the normal all lie in the same plane. 2. Light bends towards the normal when the speed of light in the second medium is less than in the first medium (or the 2nd medium is more dense) Light bends away from the normal when the speed of light in the 2nd medium is greater.

Ex.

Ray Diagram explaining the bent pencil
When light rays leave the water, they bend away from the normal (light moves faster in air then water). This makes the pencil appear to be bent and the end appears higher in the water then it actually is….

Partial Reflection and Refraction
Occurs when a beam of light has some light reflect and some light refract

Answer questions pg 519 #2, 3, 5