Waves

Question 1

What does a wave transfer?

Answer 1

Energy (from one place to another)

Question 2

What causes a wave?

Answer 2

A vibration

Question 3

What is the definition of a transverse wave?

Answer 3

The vibration causing a transverse wave is perpendicular to the direction of travel of the wave

Question 4

What is the definition of a longitudinal wave?

Answer 4

The vibration causing a longitudinal wave is parallel to the direction of travel of the wave

Question 5

Give 3 examples of longitudinal waves.

Answer 5

Sound, ultrasound and primary earthquake (P) waves

Question 6

Give 3 examples of transverse waves.

Answer 6

Water waves, all EM waves and secondary earthquake (E) waves

Question 7

What is a compression?

Answer 7

When particles in a longitudinal wave are closest together

Question 8

What is a rarefaction?

Answer 8

When particles in a longitudinal wave are furthest apart

Question 9

What is the amplitude?

Answer 9

The maximum displacement of a wave from its equilibrium position

Question 10

What is the wavelength?

Answer 10

The distance from a point on one wave to the same point on the next wave

Question 11

What is the frequency?

Answer 11

The number of waves passing a point each second

Question 12

What are the units of wave speed, wavelength and frequency?

Answer 12

Wave speed - m/s, wavelength - m, frequency - Hz

Question 13

What is the wave speed equation?

Answer 13

v = λ T

Question 14

What speed do EM waves travel at?

Answer 14

300,000,000 m/s (speed of light)

Question 15

What speed does sound travel at?

Answer 15

330 m/s

Question 16

List the EM waves in order from longest to shortest wavelength

Answer 16

Radio, microwave, infra-red, visible, ultra-violet, x-ray, gamma

Question 17

Which EM wave has the highest frequency?

Answer 17

Gamma

Question 18

Which EM wave has the most energy?

Answer 18

Gamma

Question 19

Which 3 EM waves are ionising?

Answer 19

Ultra-violet, x-ray and gamma

Question 20

What happens when light travels from air into a glass block?

Answer 20

It refracts towards the normal as glass is more dense than air

Question 21

What happens when light travels from a glass block into air?

Answer 21

It refracts away from the normal as air is less dense than glass

Question 22

What is the law of reflection?

Answer 22

The angle of incidence is equal to the angle of reflection

Question 23

What is a danger of ultra-violet radiation?

Answer 23

Increase the risk of skin cancer and cataracts

Question 24

What is a danger of x-rays and gamma rays?

Answer 24

They are both ionising radiation that can cause the mutation of genes and cancer

Question 25

What are radio waves used for?

Answer 25

TV and radio transmission

Question 26

What are microwaves used for?

Answer 26

Satellite communication (they pass through atmosphere well) and for cooking food

Question 27

What is infra-red used for?

Answer 27

Electric heaters, cooking food and infrared cameras

Question 28

What is visible light used for?

Answer 28

Fibre optic communications, visible light microscopes

Question 29

What is ultra-violet used for?

Answer 29

Detecting fake money, sun tanning

Question 30

What are x-rays used for?

Answer 30

Medical imaging and security scanning

Question 31

What are gamma rays used for?

Answer 31

Medical treatment (radiotherapy)