Reflection, Refraction and Wave Behaviour

Question 1

State the equation used to calculate wave speed. Give appropriate units.

Answer 1

Wave Speed = Frequency x Wavelength

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 2

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

Answer 2

Reflection.

Question 3

What occurs when light is reflected off a boundary?

Answer 3

It bounces off a smooth flat surface so that:

angle of incidence = angle of reflection

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.

Question 9

What are the effects of absorption of different wavelengths of waves in different mediums?

Answer 9

● Some materials behave differently depending on the wavelength
● An example is glass which will transmit
visible light, but reflect UV light

Question 10

How do sound waves travel through a solid?

Answer 10

The particles in the solid vibrate and transfer kinetic energy through the material.