waves

Question 1

what are the two types of waves

Answer 1

transverse and longitudinal

Question 2

what do waves transfer?

Answer 2

they transfer energy from one place to another

Question 3

what’s an example of transverse waves

Answer 3

ripples on water surface (transfer kinetic energy)

Question 4

what’s an example of longitudinal waves

Answer 4

sound in air (transfer sound energy)

Question 5

what do longitudinal waves require

Answer 5

medium to travel in

Question 6

what do not all transverse waves require

Answer 6

medium

Question 7

define amplitude

Answer 7

furthest point from undisturbed position

Question 8

define wavelength

Answer 8

distance between indentical points of a wave

Question 9

define frequency

Answer 9

the number of waves produced in a second

Question 10

what’s the period equation

Answer 10

period (s) = 1/ frequency (Hz)

Question 11

what’s the frequency rule

Answer 11

1 second = 1 Hertz Hz

Question 12

what’s the wave equation

Answer 12

wave speed (m/s) = frequency (Hz) x wavelength (m)

Question 13

define wave speed

Answer 13

speed at which energy is transferred

Question 14

what’s an example of an EM wave

Answer 14

light

Question 15

all EM waves are …

Answer 15

transverse

Question 16

define EM waves

Answer 16

they transfer energy from the source of the wave to an absorber

Question 17

explain how a microwave is an EM wave

Answer 17

transfers energy from the oven (source) to the food (absorber)

Question 18

what is the EM spectrum

Answer 18

radio
microwave
infrared
visible light
ultraviolet
x-ray
gamma rays

Question 19

at the start of the spectrum the properties of the waves are….

Answer 19

lower frequency and longer wavelength

Question 20

at the end of the spectrum the properties of the wave are ….

Answer 20

higher frequency and shorter wavelength

Question 21

what is the pneumonic for EM spectrum

Answer 21

Raw Meat Is Very Unsanitary eXcept Giraffes

Question 22

do EM waves need a medium to travel in?

Answer 22

No because they are transverse

Question 23

what else can EM waves travel?

Answer 23

vacuum

Question 24

do EM waves vary speeds in a vacuum

Answer 24

no they all travel in the same speed

Question 25

what speed to EM waves travel in a vacuum

Answer 25

3 x 10 to the power of 8 m/s

Question 26

different materials ….. …… or …….. EM waves

Answer 26

absorb transmit or reflect

Question 27

waves change direction when they change ……

Answer 27

speed

Question 28

when do EM waves change speed

Answer 28

moving from one medium to another

Question 29

when light passes from air to glass …….

Answer 29

the velocity of light decreases (light wave slows down) which causes direction of wave to change

Question 30

when the wave passes from the glass back to the air …

Answer 30

the velocity increases (speeds up) then they bond away from the normal

Question 31

what material allows the most IR emission

Answer 31

matt black (leslie cube)

Question 32

what material let’s the least IR radiation occur

Answer 32

shiny metallic

Question 33

which surfaces absorbs more infrared

Answer 33

matt black

Question 34

which surfaces absorbs less infrared

Answer 34

shiny metallic

Question 35

when EM waves are generated or absorbed what happens to atoms or nuclei

Answer 35

changes happen

Question 36

when atoms are heated what happens

Answer 36

electrons move from one energy level to a higher one (further from the nucleus)

Question 37

what happens when an electron returns to its original energy level

Answer 37

it generates an EM wave

Question 38

what ray can be emitted by the nucleus

Answer 38

gamma rays

Question 39

once emitted out of a radioactive atom what happens to the nucleus

Answer 39

it has less energy that at the start

Question 40

what waves are hazardous to the human body

Answer 40

UV, x-ray and gamma

Question 41

what can UV cause to humans

Answer 41

skin cancer and premature aging

Question 42

what do x-ray and gamma rays do to the human body

Answer 42

they are ionising radiation so they can cause mutation of genes (increase of cancer risk)

Question 43

what are radio waves used for

Answer 43

transmit radio and terrestrial TV signals

Question 44

give one example why radio waves used for what they are used for

Answer 44

they travel long distances

Question 45

what are microwaves used for

Answer 45

heating food communicate with satellites in space

Question 46

give one example why microwaves used for what they are used for

Answer 46

can pass through earth’s atmosphere without being reflected or refracted

Question 47

what is infrared used for

Answer 47

emitted by electrical heaters cook food in ovens infrared cameras

Question 48

give one example why infrared is used for what they are used for

Answer 48

easily absorbed by surface of objects

Question 49

what is visible light used for

Answer 49

communication using optic fibres (telephone and cable TV signals)

Question 50

what is ultraviolet used for

Answer 50

energy efficient light bulbs sun tanning (sun beds)

Question 51

give one example why UV is used for what they are used for

Answer 51

less energy needed and used

Question 52

what can we use x-rays and gamma rays for

Answer 52

medical imaging x-ray - broken bones gamma - detect cancer medical treatment- treat cancer

Question 53

give one example why x-rays and gamma rays are used for what they are used for

Answer 53

very penetrating x-rays are absorbed by bones

Question 54

what is the speed of sound in air

Answer 54

330 m/s