Waves in air, fluids and solids

Question 1

What are the 2 types of waves?

Answer 1

• Transverse.

- Longitudinal.

Question 2

What is a transverse wave?

Answer 2

A wave for which the oscillations are perpendicular to the direction of energy transfer.

Question 3

What is a longitudinal wave?

Answer 3

A wave for which the oscillations are parallel to the direction of energy transfer.

Question 4

Give 2 examples of transverse waves

Answer 4

• Electromagnetic waves.

- Seismic s-waves.

Question 5

Give 2 examples of longitudinal waves

Answer 5

• Sound waves.

- Seismic p-waves.

Question 6

What are the 2 parts of a longitudinal wave called?

Answer 6

Compressions and rarefractions.

Question 7

What is a wave’s amplitude?

Answer 7

The maximum displacement of a point on a wave from its undisturbed position.

Question 8

What is wavelength?

Answer 8

• The distance from a point on a wave to the same position on the adjacent wave.
• Most commonly peak to peak or trough to trough.

Question 9

What is the frequency of a wave?

Answer 9

The number of waves that pass a given point each second.

Question 10

What is the unit used for frequency?

Answer 10

Hertz (Hz).

Question 11

What is meant by a frequency of 200Hz?

Answer 11

200 waves pass a given point each second.

Question 12

What is wave speed?

Answer 12

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

Question 13

What does a wave transfer?

Answer 13

Energy.

Question 14

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

Answer 14

Wave speed = frequency x wavelength

Speed (m/s), frequency (Hz), wavelength (m).

Question 15

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

Answer 15

Reflection.

Question 16

How do sound waves travel through a solid?

Answer 16

The particles in the solid vibrate and transfer KE through the material.

Question 17

What is the frequency range of human hearing?

Answer 17

20 Hz - 20kHz.

1kHz - 1000 Hz

Question 18

What are ultrasound waves?

Answer 18

Waves which have a frequency higher than the upper limit of human hearing (20kHz).

Question 19

Give an example use for ultrasound waves

Answer 19

Medical or industrial imaging.

Question 20

What natural event causes seismic wave to be produced? What types are produced?

Answer 20

• Earthquakes.

- They produce both P-waves and S-waves.

Question 21

State a difference between the mediums that P-waves and S-waves can travel through

Answer 21

• P-waves travel through both solids and liquids.

- S-waves only travel through solids (not liquids).

Question 22

What technique is used to detect objects in deep water and measure water depth?

Answer 22

• Echo sounding.
• High frequency sound waves are emitted, reflected and detected.
• Time difference between emission are detected alongside wave speed, are used to calculated distances (equation for speed, distance, time).

Question 23

What property of waves in different mediums cause refraction?

Answer 23

• Velocity.

- Wave speed is slower in denser materials, causing refraction.

Question 24

In which direction do waves refract when entering a denser medium?

Answer 24

• When entering a more dense medium, the wave slows down.
• This causes the wave to bend towards the normal.
• This leads to the angle of refraction being less than the angle of incidence.