Topic 4: Waves

Question 1

What do waves transfer?

Answer 1

Energy and information

Question 2

What are the two types of waves?

Answer 2

Transverse and longitudinal

Question 3

What is a transverse wave?

Answer 3

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

Question 4

What is a longitudinal wave?

Answer 4

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

Question 5

What are some examples of transverse waves?

Answer 5

Electromagnetic waves and seismic s-waves

Question 6

What are some examples of longitudinal waves?

Answer 6

Sound waves and seismic p-waves

Question 7

What are the two parts of a longitudinal wave called?

Answer 7

Compressions and rarefaction

Question 8

What are the two parts of a transverse wave called?

Answer 8

Peaks and troughs

Question 9

What is a waves amplitude?

Answer 9

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

Question 10

What is wavelength?

Answer 10

The distance from a point on a wave to same position on the adjacent wave and most commonly peak to peak or trough or trough

Question 11

What is the frequency of a wave?

Answer 11

The number of waves that pass a given pint each second

Question 12

What is the unit used for frequency?

Answer 12

Hertz

Question 13

What is meant by a frequency of 200Hz?

Answer 13

200 waves pass a given point each second

Question 14

What is wave speed?

Answer 14

The speed at which energy is transferred through a medium

Question 15

What does a wave transfer?

Answer 15

Energy

Question 16

What is wave velocity?

Answer 16

It’s equal to the product of the wavelength and frequency of the wave

Question 17

What is the equation for wave speed?

Answer 17

Frequency x wavelength

Question 18

What is meant by the period of the wave?

Answer 18

The length of time it takes for one full wave to pass through a point

Question 19

How do sound waves travel through a solid?

Answer 19

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

Question 20

How does the human ear work?

Answer 20

The outer ear collects the sound which travels into the ear, the sound waves cause the eardrum to vibrate at the same frequency, this is amplified by three ossicles (small bones), this causes the hair in the cochlea to vibrate, the cochlea converts the vibration into electrical signals, the signals are passed to brain through the auditory nerve and the brain converts the electrical signal into sound

Question 21

What is the frequency range of human hearing?

Answer 21

20 Hz - 20kHz

Question 22

What is an ultrasound wave?

Answer 22

A sound wave with a frequency greater than 20,000 Hz

Question 23

What sound of frequencies less than 20Hz called?

Answer 23

Infrasound

Question 24

What natural event causes seismic waves to be produced?

Answer 24

Earthquakes, produce both P-waves and S-waves

Question 25

Are P-waves transverse or longitudinal?

Answer 25

Longitudinal

Question 26

Are S-waves transverse or longitudinal?

Answer 26

Transverse

Question 27

What is the difference between the mediums that P-waves and S-waves can travel through?

Answer 27

P-waves travel through both solids and liquids whereas S-waves only travel through solids

Question 28

What significance of P and S waves?

Answer 28

They provide evidence that the Earth has a liquid core; only P waves produced by an earthquake can be detected on the other side of the globe

Question 29

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

Answer 29

Echo sounding, high frequency sound waves are emitted, reflected and detected and time difference between emission and detection, alongside wave speed are used to calculate distance

Question 30

How does sonar work?

Answer 30

When ultrasound waves are emitted they reflect off boundaries and their echoes are detected, the speed of the ultrasound is known and also the time it takes to detect the echoes, the equation of distance is used to find the distance travelled and distance travelled is halved to give the distance between emitter and boundary

Question 31

How does foetal scanning work?

Answer 31

An ultrasound wave is sent into the patient body, it passes through the body and reflects off the organs and tissues, the device then uses the reflected ultrasound waves to produce an image of the foetus and the ultrasound is safe and therefore doesn’t damage cells

Question 32

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

Answer 32

Reflection

Question 33

What is the normal?

Answer 33

A vertical imaginary line which is perpendicular to the boundary

Question 34

What occurs when light is reflected off a boundary?

Answer 34

It bounces off a smooth flat surface so that the angle of incidence is same as the angle of reflection

Question 35

What is refraction?

Answer 35

Refraction is the change in speed of a wave as it reaches a boundary between two media, usually resulting in a change in direction

Question 36

What occurs when light is refracted at the boundary?

Answer 36

The light changes speed and direction in the new medium, if the new medium is more dense, the light will travel slower and bends the normal and if the new medium is less dense, the light will travel faster and bend away from the normal

Question 37

What happens to light waves when entering denser materials?

Answer 37

They slow down and bend towards the normal

Question 38

What happens to light waves when entering less dense materials?

Answer 38

They sped up and bend away from the normal

Question 39

How can refraction be measured?

Answer 39

The angle of incidence and angle of refraction can be measured and compared, all angles are measured relative to the normal

Question 40

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

Answer 40

Some materials behave differently depending on the wavelength

Question 41

How do sound waves travel through a solid?

Answer 41

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