(6) Waves in Air, Fluids and Solids

Question 1

What are the two types of waves?

Answer 1

Transverse and longitudinal

Question 2

What is a transverse wave?

Answer 2

A wave for which the oscillations are perpendicular to the direction of energy transfer. Like ripples on a water surface.

Question 3

What is a longitudinal wave?

Answer 3

A wave for which the oscillations are parallel to the direction of energy transfer. They show areas of compression and rarefaction (regions of low pressure due to particles being spread apart)

Question 4

What are two examples of transverse waves?

Answer 4

• electromagnetic waves
• seismic waves

Question 5

What is an example of a longitudinal wave?

Answer 5

• sound waves

Question 6

What is a waves amplitude?

Answer 6

The maximum displacement of a point on a wave from its un disturbed position

Question 7

What is a wave length?

Answer 7

The distance from a point on a wave to the same position on the adjacent wave (peak to trough)

Question 8

What is the frequency of a wave and the unit?

Answer 8

The number of waves that pass a given point each second. In hertz (Hz)

Question 9

What is wave speed?

Answer 9

The speed at which the wave moves or at which energy is transferred through a medium

Question 10

What does a wave transfer?

Answer 10

Energy

Question 11

What is the equation to calculate wave speed?

Answer 11

Wave speed = frequency x wavelength

Question 12

How do you measure the speed of ripples on waters surface?

Answer 12

A ripple tank

Question 13

What is reflection?

Answer 13

When a wave bounces off a surface, usually at the boundary between two different materials. This can be investigated using a ripple tank

Question 14

What happens to plane waves when reflected in a ripple tank?

Answer 14

Plane waves in a ripple tank are reflected from a straight barrier at the same angle to the barrier as the incident waves. Their speed and wavelength do not change on reflection

Question 15

What is the refraction of waves?

Answer 15

The waves change direction in which they are travelling when they cross a boundary between two different materials (in a ripple tank it could be deep and shallow water).

Question 16

What happens to plane waves when refracted?

Answer 16

There is a change in speed and direction. The wavefronts move more slowly after they have crossed the boundary so the refracted waves are at a smaller angle and closer together (still same frequency)

Question 17

When can waves be transmitted or absorbed?

Answer 17

At the boundary of two different materials or mediums. If the substance absorbs the waves it will gain energy and possibly be heated up.