P1.5

Question 1

Sound waves…

Answer 1

…are vibrations in a medium and cannot travel through a vacuum

Question 2

What is a mechanical wave?

Answer 2

Vibrations that travel through a substance (cannot travel through a vacuum) - can be traverse or longitudinal

Question 3

What do waves transfer?

Answer 3

Energy, communications and information

Question 4

What is a longitudinal wave?

Answer 4

The oscillations are parallel to the direction of energy transfer

Question 5

What is a transverse wave?

Answer 5

The oscillations are perpendicular to the direction of energy transfer

Question 6

What is an example of a longitudinal wave?

Answer 6

Sound waves

Question 7

What is an example of a transverse wave?

Answer 7

Electromagnetic waves

Question 8

Longitudinal show areas of compression and rarefraction

Answer 8

Compression= squashed together and rarefraction = spread apart

Question 9

Name the waves in the electromagnetic spectrum

Answer 9

Rapid - radio
Monkeys - microwave
In - infrared
Velvet - visible
Underpants - ultra violet
eXcrete - X-rays
Gummybears - gamma

Question 10

Radio waves have…

Answer 10

…little energy, low frequency and low wavelength (10 power15)

Question 11

Gamma waves have…

Answer 11

…most energy, highest frequency & highest wavelength (10 power4)

Question 12

Waves can be…

Answer 12

…relflected, refracted and diffracted

Question 13

What is reflection?

Answer 13

Image is formed that is virtual, upright and laterally inverted

Question 14

The angle of incidence=

Answer 14

The angle of reflection

Question 15

What is refraction?

Answer 15

The change of direction of a light ray as it passes across a boundary between two transparent substances

Question 16

What happens to the wave when it goes from air to glass?

Answer 16

It bends towards the normal and slows down

Question 17

What happens to the wave when it goes from glass to air?

Answer 17

It bends away from the normal and speeds up

Question 18

What happens to the wave when it goes from air to glass at 90 degrees/along the normal?

Answer 18

It does not refract/carries on at 90degrees

Question 19

What is the amplitude of a wave?

Answer 19

The height of a wave crest or a wave trough of a transverse wave from the rest position

Question 20

What is the wavelength of a wave?

Answer 20

The distance of one wave crest to the next wave crest - measured in m

Question 21

What is the frequency of a wave?

Answer 21

The number of wave crests passing a fixed point every second - measured in hertz

Question 22

What is the wave speed of a wave?

Answer 22

Wavelength x frequency

Question 23

What are radio waves used for?

Answer 23

Communications - tv, radio and mobile phone signals

Question 24

What are microwaves used for?

Answer 24

Cooking and communications - phones and tv

Question 25

What are infrared waves used for?

Answer 25

Communications - remote controls & optical fibres

Question 26

What are visible waves used for?

Answer 26

Communications - photography

Question 27

What are ultra violet waves used for?

Answer 27

Sunbeds & forged bank notes

Question 28

What are x-Rays used for?

Answer 28

Bone fractures & seeing inside the body

Question 29

What are gamma rays used for?

Answer 29

Grating cancer & sterilising equipment

Question 30

What are reflected sound waves known as?

Answer 30

Echos

Question 31

What affects the pitch of a note?

Answer 31

The frequency of a wave

Question 32

What affects the volume of a wave?

Answer 32

The amplitude of the wave

Question 33

What is diffraction?

Answer 33

The spreading of waves when they pas through a gap or around the edge of an obstacle which has a similar size as the wavelength of the waves

Question 34

What is the Doppler effect?

Answer 34

The change of wavelength and frequency of a wave (light from galaxies, sounds or microwaves) as it moves towards or away from the observer

Question 35

What is red-shift?

Answer 35

The movement of a wave towards the red end of the spectrum so the wave moves away from the observer - increased wavelength and decreased frequency

Question 36

What is blue-shift?

Answer 36

The movement of a wave towards the blue end of the spectrum so the wave moves towards the observer - decreased wavelength and increased frequency

Question 37

Red shift =

Answer 37

Evidence the universe is expanding

Question 38

Red-shift of galaxies?

Answer 38

Light from distant galaxies are moving away from us so have an increased wavelength and decreased frequency - the light appears more red

Question 39

What does the further away the distant galaxies tell us about them?

Answer 39

The faster the galaxies are moving and the bigger increase in wavelength

Question 40

What is the Big Bang theory?

Answer 40

The theory the universe started from a very small initial point

Question 41

What is cosmic microwave background radiation?

Answer 41

Electromagnetic radiation which fills the universe. It comes from the radiation present after the Big Bang so provides evidence for the Big Bang theory

Question 42

What are electromagnetic waves?

Answer 42

Electric or magnetic disturbances that transfer energy from one place to another. They travel through a vacuum at the same speed (3000000km/s = speed of light)

Question 43

What is the problem with using your mobile phone a lot (especially near you head)?

Answer 43

Microwaves are transferred between your phone and the bearest transmitter Some wavelengths of microwaves are absorbed by water and heats it up so this happens with the water in your cells and so lead to damaged health but there's no evidence yet