REFRACTION

Page 1 of 4

When a wave travels from one medium to another, at an angle, it changes direction.

Here is a wave. Imagine its a ray of light from a laser.

I hope you remember what these are:

Speed
Wavelength
Frequency
Amplitude

This wave is travelling at 3 x 108 m/s    All electromagnetic waves travel at this speed in air.

What happens if this wave goes into a block of glass? Which of the things listed above will change?

Speed - this is smaller. The wave slows down. It is now about 2.5 x 108 m/s
Wavelength - this is smaller too
Frequency - this must be the same. The number of waves going in every second must equal the number of waves coming out.
Amplitude - this is unchanged

Here's another way of looking at lt. These lines are called "wavefronts". The distance between 2 of them is a wavelength.

So what happens if the ray enters the glass at an angle?

Lets go to Page 2 and find out.