3. Waves

Question 1

definition of transverse wave

Answer 1

wave where the direction of oscillation is perpendicular to the direction of energy transfer.

Question 2

definition of longitudinal wave

Answer 2

wave where the direction of oscillation is parallel to the direction of energy transfer.

Question 3

definition of amplitude

Answer 3

distance from the equilibrium position to the peak of a wave

Question 4

definition of wavefront

Answer 4

???

Question 5

definition of frequency

Answer 5

number of complete oscillations per second

Question 6

definition of wavelength

Answer 6

distance from the peak of one crest to the peak of an adjacent crest ( next peak along)

distance for 1 full oscillation

Question 7

definition of (time) period

Answer 7

time taken for 1 complete oscillation

Question 8

what 2 things do waves transfer and how

Answer 8

energy and information by an oscillation

Question 9

wave speed equation

Answer 9

wave speed = frequency x wavelength

Question 10

frequency equation

Answer 10

frequency = 1 / time period

Question 11

time period equation

Answer 11

time period = 1 / frequency

Question 12

example of transverse wave

Answer 12

light
all electromagnetic waves
mechanical waves ( water)

Question 13

example of longitudinal wave

Answer 13

sound
compressive slinky wave
seismic P - wave

Question 14

what is the Doppler effect

Answer 14

???

Question 15

what can happen to all waves (rrd)

Answer 15

reflected
refracted
diffracted

Question 16

definition of an electromagnetic wave

Answer 16

waves with an electric and magnetic component at 90 degrees to one another

all transverse

travel at same speed through a vacum

Question 17

What is the order of the EM spectrum with increasing frequency?

Answer 17

Radio, Micro, IR, Light, UV, X, Gamma

Question 18

What is the order of the EM spectrum with increasing wavelength?

Answer 18

Gamma, X, UV, Light, IR, Micro, Radio

Question 19

What is the order of the colours in increasing frequency?

Answer 19

Red Orange Yellow Green Blue Indigo Violet

Question 20

What is the order of the colours in increasing wavelength?

Answer 20

Violet Indigo Blue Green Yellow Orange Red

Question 21

what is the use of radio waves

Answer 21

broadcast communications

Question 22

what is the use of microwaves

Answer 22

cooking 
satellite transmissions (communications)

Question 23

what is the use of IR

Answer 23

heaters

night vision equipment

Question 24

what is the use of visible light

Answer 24

photography

optic fibres

Question 25

what is the use of UV

Answer 25

Tanning salon | fluorescent lamps

Question 26

what is the use of x-rays

Answer 26

observing the internal structure of objects and materials incl. medical purposes

Question 27

what is the use of gamma rays

Answer 27

sterilising food | radio therapy

Question 28

dangers of microwaves

Answer 28

internal tissue heating

Question 29

dangers of IR

Answer 29

skin burns

Question 30

dangers of visible light

Answer 30

blindness

Question 31

dangers of UV

Answer 31

ABC Aging Burning Cancer

Question 32

dangers of x-rays

Answer 32

cancer

Question 33

danger of gamma rays

Answer 33

cell mutation cancer (kill things )

Question 34

protection from microwaves

Answer 34

microwaves oven have shielding

Question 35

protection from IR

Answer 35

insulating materials

Question 36

protection from visible light

Answer 36

sun glasses

Question 37

protection from UV

Answer 37

sun cream

Question 38

protection from x-rays and gamma rays

Answer 38

lead

Question 39

what is the law of reflection

Answer 39

angle of incidence = angle of reflection

Question 40

what is snells law ( refractive index equation)

Answer 40

refractive index of the medium= sin(angle of incidence) / sin(angle of refraction) n= sin ( i ) / sin ( r )

Question 41

definition of total internal reflection

Answer 41

????transmit information along optical fibres and in prisms ???core cladding refactive index must be lower than central core when angle of incidence is greater than critical angle

Question 42

uses of total internal reflection

Answer 42

optic fibre lamps periscope endoscope

Question 43

what is the critical angle, C

Answer 43

angle of reflection = 90 degrees = refracted ray travels along the boundary

Question 44

equation for critical angle ( snells law)

Answer 44

sin ( critical angle ) = 1 / refractive index of material sin ( C ) = 1 / n the higher the refractive index the lower the critical angle

Question 45

PAPER 2 what is the frequency range for human hearing

Answer 45

20 - 20,000 Hz 20Hz- 20kHz

Question 46

PAPER 2 how are an oscilloscope and microphone used to display a sound wave

Answer 46

??? Plug microphone into oscilloscope Microphone picks ups sound waves travelling through air Microphone converts sound waves to electrical signals Oscilloscope displays microphone signal as trace on the screen ( squiggly lines ( up & down) )

Question 47

PAPER 2 what is loudness determined by

Answer 47

amplitude- the higher the amplitude the louder the sound

Question 48

PAPER 2 what is pitch determined by

Answer 48

frequency- the higher the frequency the higher the pitch

Question 49

PAPER 2 when a sound wave has a large frequency how does it sound

Answer 49

high pitched

Question 50

PAPER 2 when a sound wave has a large amplitude how does it sound

Answer 50

loud

Question 51

PAPER 2 when a sound wave has a low frequency how does it sound

Answer 51

low pitched

Question 52

PAPER 2 when a sound wave has a large amplitude how does it sound

Answer 52

quiet

Question 53

PAPER 2 what is ultra sound

Answer 53

sound waves above 20,000Hz