waves

Question 1

what type of waves are p-waves

Answer 1

p-waves are longitudal

Question 2

what type of waves are s-waves

Answer 2

s-waves are transverse

Question 3

what is a progressive wave

Answer 3

an oscillation that travels through matter and transfers energy, not matter

Question 4

what happens to particles when a progressive wave moves to a new mdian

Answer 4

they move from their original position to a new position

Question 5

what happens to a displaced particle once a wave enters a nwe mdian

Answer 5

it experiences a restoring force from its neighbours that pull it back to its original position

Question 6

what are peaks and troughs

Answer 6

this is when the oscillating particles are at a maximum displacement from their equillibrium position

Question 7

what happens to particles as sound waves move through the air

Answer 7

air particles are displaced and bounce off their neighbours causing collisions which provide a restoring force

Question 8

amplitude

Answer 8

maximum displacement from the equilibrium position

Question 9

wavelength

Answer 9

minimum distance between two points in phase on adjacent waves

Question 10

period

Answer 10

the time taken for one oscillation

Question 11

frequency and period equation

Answer 11

f = 1/T

Question 12

phase difference

Answer 12

phase difference describes the difference between the displacements of particles along a wave or the displacements of particles on different waves

measured in degrees or radians

Question 13

what degree means particles are in antiphase

Answer 13

pi radians

Question 14

equation for phase difference between two points on a wave

Answer 14

phi = (x(distance) / wavelength)*360

Question 15

two types of graphs to show waves

Answer 15

-displacemet distance graphs
-displacement time graphs

Question 16

what can be used to determine the frequency of a wave

Answer 16

oscilloscope

Question 17

what does each horizontal square on an oscilloscope represent

Answer 17

timebase

Question 18

what is reflection

Answer 18

reflection occurs when a wave changes direction at a boundery between two different media, while remaining in the same medium

Question 19

law of angle of reflection

Answer 19

angle of incidence = angle of reflection

Question 20

what is rarefraction

Answer 20

rarefraction occurs when a wave changes direction as it changes speed when it passes from one median to another

Question 21

what happens when a rarefracted wave slows down

Answer 21

the wave bends towards the normal

Question 22

what happens when a rarefracted wave speeds up

Answer 22

the wave bends away from the normal

Question 23

what is affected when a wave rarefracts

Answer 23

wavelength and wave speed

Question 24

what happens to the wavelength of a refracted wave when it speeds up

Answer 24

wavelength increases and vice versa

Question 25

what is diffraction

Answer 25

the way a wave spreads out as it passes through a gap or goes around an obstacle

Question 26

what changes when diffraction occurs

Answer 26

nothing, speed wavelength and frequency remain constant

Question 27

when are diffraction effects most significant

Answer 27

they are most significant when the size of the gap or obstacle is about the same as the wavelength of the wave.

Question 28

what is polarisation

Answer 28

polarisation is when a particle oscillates in one direction and is confined to a single plane

Question 29

when is a wave said to be plane polarised

Answer 29

when the wave is confined to a single plane and only oscillates in one direction

Question 30

can longitudinal waves be polarised

Answer 30

no as the oscillations are always confined to one plane

Question 31

what happens when a transverse wave frelects off a surface

Answer 31

they become partially polarised meaning there are more waves oscillating in one particular plane but the wave is not completelyt plane polarised

Question 32

instensity definition

Answer 32

the radiant power passing through a surface per unit area

Question 33

instensity equation

Answer 33

I = P/A

Question 34

relation between amplitude and intensity

Answer 34

intensity is directly proportional to (amplitude)^2

Question 35

what are EM waves

Answer 35

EM waves can be thought off as electric and magnetic fields oscillating at right angles to each pther

Question 36

how are gamma and x-rays identified in the overlap region

Answer 36

they are identified by their origin x-rays are identified by fast moving electrons whearaas gamma rays come from unstable atomic nuclei

Question 37

refractive index

Answer 37

a material property that describes how the material affects the speed of light travelling through it

Question 38

refractive index equation

Answer 38

n = c/v

Question 39

two refraction law equations

Answer 39

nsin(theta) = K n1sin1(theta) = n2sin2(theta)

Question 40

principle of superposition

Answer 40

when two waves meet at a point the resultant displacement at that point is equal to the sun=m of the displacemts of the original waves

Question 41

what is interferacne

Answer 41

when two progressive waves continously pass through each other they superpose and produce a resultant wave

Question 42

what is constructive interferance

Answer 42

when two waves are in phase there is maxiumum positive displacement from wach wave line up

Question 43

what is coherence

Answer 43

waves that are emitted from two sources and have a constant phase difference

Question 44

what do interference patterns contain a series off?

Answer 44

they contain a series of maxima and minima

Question 45

what happens at maxima in interference patterns

Answer 45

the waves interfere constructivley

Question 46

what happens at minima in interference patterns

Answer 46

the waves interfere destructivley

Question 47

what is path difference between two waves

Answer 47

the differnce between the distance travelled between two waves from their sources to a point

Question 48

what condition is needed for two coherent waves to arrive at a point in phase

Answer 48

they waves will arive in phase if the path differnce is 0 or a whole number of wavelengths. this results in constructive interfernce and a higher amplitude

Question 49

what condition is needed for two coherent waves to arrive at a point in antiphase

Answer 49

the waves will arive in antiphase if the pth difference to a point is an odd number of half wavelengths

Question 50

what light source must be used in youngs double slit experiment

Answer 50

monochromatic light so that only a specifc frequency of light can pass through

Question 51

explain the first bit of youngs

Answer 51

monochromatic light enters the first single slit. it diffracts and arrives at the double slit in phase. it diffracts again from the double slit which acts as a source of two coherent waves which spread from each slit, overlapping and forming an interfernce pattern that can be seen on the screen as a pattern off bright and dark regions called fringes

Question 52

what did youngs double slit show

Answer 52

the experiment displayed the wave nature of light

Question 53

one equation for youngs

Answer 53

wavelength = seperation between two slits*seperation between fringes / distance to the screen

Question 54

approx wavlength of radio

Answer 54

10^-1 to 10^6

Question 55

approx wavlength of micro

Answer 55

10^-3 to 10^-1

Question 56

approx wavelgnth of IR

Answer 56

(10^-7 to 10^-3)

Question 57

approx wavelength of visable light

Answer 57

(4*10^-7) to (7*10^-7)

Question 58

approx wavlength of uv

Answer 58

(10^-8) to (10^-7)

Question 59

approx wavlength of x-rays

Answer 59

10^-13 to 10^-8

Question 60

approx wavelength of gamma

Answer 60

10^-16 to 10^-10

Question 61

what is a stationary wave

Answer 61

a stationary wave is the superposition of two progressive waves with the same wavelength moving in opposite directions

Question 62

what differs between progressive waves and stationary

Answer 62

no energy is transmitted by a stationary wave