Light an Optics Unit

For the last couple of weeks, we were learning about light,mirrors and lenses. One main idea was about refraction which is a change in direction due to a change in medium.

Key Ideas

• Path of Least Time: light will find the quickest route to an endpoint
• If there is one medium/material, the path of least time will be a straight line from start to finish.
• If there are two mediums/materials (2 velocities), the path of least time will be at the point that the medium changes which is ultimately refraction.

Snell's Law

This law allows us to find the straw's angle of refraction from air to water. As you can see from the picture above, the pencil looks like it's bending when it changes medium.

Air: index of refraction=1

Water: index of refraction=1.33