t6-waves

Question 1

properties of waves

Answer 1

-transfer energy
-can be described as oscillations/vibrations

Question 2

what are longitudinal waves

Answer 2

vibrations are parallel the direction of the wave movement

Question 3

3 examples of longitudinal waves

Answer 3

sound waves
ultrasound waves
seismic p-waves

Question 4

what are transverse waves

Answer 4

vibrations are perpendicular to the direction of the wave movement

Question 5

3 examples of transverse waves

Answer 5

ripples on water surface
electromagnetic waves
seismic s-waves

Question 6

what are electromagnetic waves

Answer 6

they’re transverse waves
vibrations are changes in electrical/magnetic fields perpendicular to the direction of the wave movement

Question 7

2 properties of electromagnetic waves

Answer 7

-they transfer energy as radiation from the source of the waves to the absorber
-can travel through a vacuum as no particles are needed

Question 8

what are mechanical waves

Answer 8

can be transverse or longitudinal
cause vibrations of particles in a substance

Question 9

one property of mechanical waves

Answer 9

-can’t travel through a vacuum- they need a medium to travel

Question 10

what 3 things can happen to a wave when it hits a surface

Answer 10

transmission
absorption
reflection

Question 11

what happens for a wave to be reflected

Answer 11

if an incident ray hits the boundary between 2 substances
the energy of the wave is reflected with the wave and doesn’t enter the substance

Question 12

what happens during absorption of a wave

Answer 12

if waves enter a substance, some/all of the wave can be absorbed, and the wave energy transforms into thermal energy and increases the temperature of the substance

Question 13

what happens to images in a plane mirror

Answer 13

-they’re the same size
-laterally inverted
-same distance
-virtual

Question 14

what do wave fronts represent

Answer 14

the crest of a wave

Question 15

what is refraction

Answer 15

the change in direction of a wave at a boundary

Question 16

how does the density of a material affect a wave

Answer 16

it affects the speed the wave will be transmitted through it
the denser the material, the slower the wave travels through it

Question 17

what happens as a wave moves from less to more dense substance

Answer 17

ray bends towards the normal and it slows down

Question 18

what happens as a wave moves from more to less dense substance

Answer 18

ray bends away from the normal and it speeds up

Question 19

what is the relationship between wave speed and wavelength

Answer 19

they’re directly proportional so if a wave slows down, wavelength will decrease, so wave fronts are closer together

Question 20

2 properties of sound waves

Answer 20

-longitudinal
-travels more efficiently through solids as the particles are closer together

Question 21

properties of p waves

Answer 21

-longitudinal
-travel faster
-travel through solid and liquid

Question 22

properties of s waves

Answer 22

-transverse
-travel slower
-travel through solid

Question 23

properties of radiowaves and uses

Answer 23

-long wavelength
-transmitted easily through air
-don’t cause damage
-can be reflected to change direction
-used for communications

Question 24

how are radiowaves produced

Answer 24

-by oscillations in electric circuits
-when radiowaves are absorbed by conductor, they create an alternating current
-electric current has same frequency as radiowaves

Question 25

uses of microwaves

Answer 25

-used for cooking food and satellite communications
-high frequency microwaves can be absorbed by food
-the internal energy of molecules increases when food absorbs microwaves so it heats up

Question 26

uses of infrared

Answer 26

-electrical heaters
-cookers
-infrared cameras

Question 27

properties of infrared

Answer 27

-long wavelength
-frequencies absorbed by some chemical bonds. Internal energy of bonds increases when infrared is absorbed so it heats up. Useful for cookers and electrical heaters
-all objects emit infrared

Question 28

use of visible light

Answer 28

-fibre optic communications

Question 29

properties and use of UV light

Answer 29

-hazardous to body
-Fluorescent substances are used in energy-efficient lamps. They absorb UV light inside the lamp, and re-emit the energy as visible light.