Refraction

Refraction - Waves Change Speed and Direction...

The speed of a wave is determined by the density of the substance or medium it's travelling in.

So when a wave cfrosses a boundary between two substances (e.g. glass to air), it changes speed.

Since Wave Speed = Frequency x Wavelength and the frequency is fixed for each type of wave, then is the speed changes, the wavelength must also change. E.g. if speed decreases, the wavelength must decrease.

Remeber:

• If light hits the medium straight on, it will slow but will carry on in the same direction.
• But if the wave meets a new medioum at an angle, part of this wave hits the boundary first and slows…