Physics CT3

Question 1

define amplitude

Answer 1

the maximum displacement of a wave particle from equilibrium

Question 2

define wavelength

Answer 2

the distance between one crest/trough to the next one

Question 3

define frequency

Answer 3

how many waves pass ever second

Question 4

define speed

Answer 4

how fast a wave travels

Question 5

define time period

Answer 5

the length of time it takes for one wave to pass a point

Question 6

define a transverse wave

Answer 6

the oscillations are perpendicular to the waves direction of travel.

Question 7

define a longitudinal wave

Answer 7

the oscillations are parallel to the waves direction of travel

Question 8

define displacement

Answer 8

a measure of distance in a given direction from point to point

Question 9

define compression

Answer 9

regions where particles are close together

Question 10

define rarefraction

Answer 10

regions where particles are further apart

Question 11

define oscillation

Answer 11

describes the movement and vibrations of particles back and forth

Question 12

calculation for velocity

Answer 12

frequency x wavelength

Question 13

define refraction

Answer 13

the change in speed that causes the light to change direction

Question 14

define interface

Answer 14

the line between two serfaces

Question 15

define the normal

Answer 15

-line 90 degrees to the interface
-shown as a dotted line

Question 16

define the ray of incidence

Answer 16

the ray that is going in

Question 17

define the ray of refraction

Answer 17

the ray that bends

Question 18

what happens to the direction of the wave when is slows down

Answer 18

it is refracted towards the normal

Question 19

what happens to the direction of the wave when it speeds up

Answer 19

it is refracted away from the normal

Question 20

why do prescription glasses refract the light

Answer 20

it bends the light so people can see as the light is then focused

Question 21

what is the order of the electromagnetic wave spectrum

g-r

Answer 21

-gamma
-x rays
-ultra violet
-visible light
-infrared
-microwaves
-radio`

Question 22

when will heat stop spreading from high temperature materials to lower temperature materials

Answer 22

until it reaches thermal equilibrium

Question 23

define thermal equilibrium

Answer 23

if the heat absorbed each second by an object matches the heat emitted per second by an object

Question 24

what happens if the object is really hot

Answer 24

radiate more wavelengths and higher frequency wavelength

Question 25

how much energy do emag waves transfer when they have a high frequency

Answer 25

lLOTS

Question 26

what are shorter wavelength emag waves used for

Answer 26

to sterilise- to kill bacteria cells- things (food, surgical instruments, toothbrushes)

Question 27

what are gamma rays used for

Answer 27

destroy cancerous cells in the body and to sterilise food and surgical equipment

Question 28

define tracer solution

Answer 28

a liquid containing a gamma -emitting isotope- is injected into the body

Question 29

What is the law of refelction

Answer 29

the angle of reflection is equal to the angle of incidence

Question 30

what are the key points of the refraction practicle

Answer 30

-draw normal -mark path of ray in and out of block with crosses -join up the crosses with straight lines -measure angles from normal to ray

Question 31

define diffuse reflection

Answer 31

when materials have rough surfaces so the reflected light is scattered in all directions

Question 32

define specular reflection

Answer 32

when smooth surfaces reflect the light evenly

Question 33

define white light

Answer 33

it is a mixture of different colours that our eyes see as white

Question 34

what happens to the wavelength when there is an increase in temperature

Answer 34

it gets shorter

Question 35

define the power

Answer 35

the amount of energy transferred in a certain time

Question 36

how much radiation does the earths surface absorb from the sun

Answer 36

around half

Question 37

what type of radiation does the earth re radiate the sun energy to

Answer 37

infrared radiation

Question 38

what does the earth do to make sure it stays the same temperature

Answer 38

it must radiate energy into space at the same average rate is is absorbed