Wave Behaviour

Question 1

What word is used to describe when a wave bounces off a surface?

Answer 1

Reflection

Question 2

What is the normal (in terms of reflection and refraction)?

Answer 2

A vertical imaginary line which is perpendicular to the boundary

Question 3

What occurs when light is reflected off a boundary?

Answer 3

It bounces off a smooth flat surface so that the angle of incidence (the angle it comes in at) is the same as the angle is reflection (the angle it leaves at).

Question 4

What is refraction?

Answer 4

Refraction is the change in speed of a wave as it reaches a boundary between two media, usually resulting in a change in direction (if it enters at an angle).

Question 5

What occurs when light is refracted at a boundary?

Answer 5

• The light changes speed and direction in the new medium
• If the new medium is more dense, the light will travel slower and bend towards the normal
• If the new medium is less dense, the light will travel faster and bend away from the normal

Question 6

When entering a denser material, light waves…

Answer 6

…slow down and bend towards the normal

Question 7

When entering a less dense material, light waves…

Answer 7

…speed up and bend away from the normal

Question 8

How can refraction be measured?

Answer 8

The angle of incidence, i, and angle of refraction, r, can be measured and compared. All angles are measured relative to the normal.