PHY TOPIC 6 WAVES

Question 1

amplitude

Answer 1

maximum displacement of a point on the wave from its undisturbed position

Question 2

wavelength

Answer 2

distance between the same point on two adjacent waves (i.e. between two troughs)

Question 3

frequency

Answer 3

number of complete waves passing a certain point per second, measured in Hz. 1 Hz is 1 wave per second

Question 4

period

Answer 4

time taken for one full cycle of a wave

Question 5

All waves are either

Answer 5

transverse or longitudinal

Question 6

Transverse waves definition

Answer 6

the oscillation are perpendicular to the direction of energy transfer.

Question 7

Transverse waves examples x3

Answer 7

• all electromagnetic waves e.g light
• ripples on the surface of water
• a wave on a string

Question 8

longitudinal wave definition

Answer 8

the oscillations are parallel to the direction of energy transfer

Question 9

longitudinal examples x2

Answer 9

sound waves in air
shock waves e.g some seismic waves

Question 10

Wave speed equation

Answer 10

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

Question 11

wave speed definition

Answer 11

the speed at which energy is being transferred through a medium

Question 12

waves tranfer energy…

Answer 12

in the direction they are travelling

Question 13

when waves travel through a medium….

Answer 13

the particles of the medium oscillate and transfer energy between each other. BUT overall the particles stay in the same place - only energy is transferred.

Question 14

all waves can be …

Answer 14

absorbed, transmitted or reflected

Question 15

absorption

Answer 15

energy is transferred to the materials energy stores

Question 16

transmission

Answer 16

the waves carry on travelling through the new material. Often leading to refraction

Question 17

reflection

Answer 17

the waves bounce back off the boundary.

Question 18

gamma rays are produced by

Answer 18

changes in the nucleus of an atom

Question 19

how are waves with frequencies from infrared up to x- rays produced?

Answer 19

Electrons rearranging themselves inside atoms.

Question 20

radio waves are produced

Answer 20

outside the atom by oscillating charged particles. e.g electrons in a circuit.

Question 21

the same processes that produce em waves

Answer 21

happen in reverse when they are absorbed.

Question 22

if a wave enters a boundary and speeds up

Answer 22

it bends away from the normal

Question 23

if a wave enters a boundary and slows down

Answer 23

it bends towards the normal

Question 24

when a wave is refracted

Answer 24

its wavelength changes but frequency stays the same

Question 25

optical density of a material =

Answer 25

measure of how quickly light travels through it

Question 26

the higher the optical density

Answer 26

the slower light travels through it.

Question 27

Radiation dose is.... measured in...

Answer 27

a measure of the risk of harm from the body being exposed to radiation. sieverts