Relevant Waves

Question 1

What happens when waves travel through a medium

Answer 1

The particles oscillate and transfer energy between each other but overal the particles stay in the same - only energy is transferred

Question 2

What is the aplimitude of a wave

Answer 2

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

Question 3

What is the wavelength

Answer 3

the distance from a point on one wave to the equivalent point on the adjacent wave.

Question 4

What is the frequency of a wave

Answer 4

The number of completed waves passing a certain point per second. Frequency is measured in herts

Question 5

What is an example of a transverse wave

Answer 5

The ripples on a water surface or a wave of a string

Question 6

Transverse waves characteristics

Answer 6

The oscillations (vibrations) are perpendicular to the direction of energy transfer

Question 7

Longitudal wave characteristics

Answer 7

The oscillations are parallel to the direction of energy transfer

Question 8

Examples of longitudal waves

Answer 8

Sound waves or shock waves

Question 9

Movements of longitudal waves

Answer 9

They refract and compress

Question 10

What is wave speed

Answer 10

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

Question 11

What is the crest and trough of a wave

Answer 11

Top and bottom

Question 12

How can waves be reflected

Answer 12

Waves can be reflected at the boundary between two different materials. Waves can be absorbed or transmitted at the boundary between two different materials.

Question 13

Angle of incidence =

Answer 13

Angle of refraction

Question 14

What three things can happen when waves arrive at a boundry between two different materials

Answer 14

• reflect
• absorb
• tansmitt (leads to refraction)

Question 15

What affects how waves do when arrive at two different objects

Answer 15

What happens depends on the wavelength and the properties of the materials involved

Question 16

What is the angle of incidence

Answer 16

The angle between the incoming wave and the normal

Question 17

What is the angle of refraction

Answer 17

The angle between the reflected wave and the normal

Question 18

What is the normal

Answer 18

a line perpendicular to the surface at the point of incidence

Question 19

What is specular reflection

Answer 19

Happens when waves reflec a single direction by a smooth surface.

Question 20

What is diffuse reflection

Answer 20

When a wave is reflected by a rough suface and the reflected rays are scattered as the normal is different for each incidence ray.

Question 21

What affect refraction

Answer 21

How the wave speeds up or slows down depending on density of two materials

Question 22

What happens when a wave crosses a boundry and slows down

Answer 22

The light will bend towards the normal (opposite for when it speeds up)

Question 23

How does the waves change when refracted

Answer 23

The frequency stays the same but the wavelength changes

Question 24

How can sound waves travel

Answer 24

Sound waves can travel through solids causing vibrations in the solid.

Question 25

How do sounds waves get heard by humans

Answer 25

Within the ear, sound waves cause the ear drum and other parts to vibrate which causes the sensation of sound. The conversion of sound waves to vibrations of solids works over a limited frequency range. This restricts the limits of human hearing.

Question 26

Why can sound only work over limited frequency range and the relevance of this to human hearing.

Answer 26

Different materials can convert different frequencies of sound waves into vibrations. (Humans can only hear 20Hz - 20kHz). Humans hearing is limited by the size and shape of our ear drum, as well as the structure of all parts within the ear that vibrate to transfer energy from sound waves.

Question 27

When will sound waves refract

Answer 27

As they enter denser material and speed up as the waves travel into a different medium.

Question 28

How can sound waves be used for ultrasound

Answer 28

Ultrasound waves have a frequency higher than the upper limit of hearing for humans. (20,000Hz) Ultrasound waves are partially reflected when they meet a boundary between two different media. The time taken for the reflections to reach a detector can be used to determine how far away such a boundary is. This allows ultrasound waves to be used for both medical and industrial imaging.

Question 29

How can uktrasound be used

Answer 29

Medical imaging: be used to detect the boundry of fluid in womb and foetus, with some waves being reflected back.
Industrial imaging: crack in materias can be detected by waves reflecting out of them

Question 30

How can waves be used to detect or explore

Answer 30

Waves can be completely reflected or partically. The wave may continue travelling in the same direction but at different speeds, or may be refracted. Strudying these path and properties can help show properties of structures that you can’t see.

Question 31

How are seismic waves produced

Answer 31

Seismic waves are produced by earthquakes

Question 32

P-waves

Answer 32

P-waves are longitudinal, seismic waves. P-waves travel at different speeds through solids and liquids.

Question 33

S-waves

Answer 33

S-waves are transverse, seismic waves. S-waves cannot travel through a liquid.

Question 34

What can measuring P/S-waves do

Answer 34

P-waves and S-waves provide evidence for the structure and size of the Earth’s core.

Question 35

Echo sounding

Answer 35

Echo sounding, using high frequency sound waves is used to detect objects in deep water and measure water depth.