P3 waves

Question 1

what do waves transfer

Answer 1

energy, WITHOUT transferring matter

Question 2

describe transverse wave

Answer 2

direction of vibration at right angle to direction of propagation

Question 3

examples of transverse waves

Answer 3

• electromagnetic radiation
• water waves
• seismic S-waves

Question 4

describe longitudinal wave

Answer 4

direction of vibration is parallel to direction of propagation

Question 5

examples of longitudinal waves

Answer 5

• sound waves
• seismic P-waves

Question 6

features of a wave

Answer 6

• wavelength
• frequency
• crest (peak)
• trough
• amplitude
• wave speed

Question 7

equation for wave speed

Answer 7

Question 8

what causes the refraction of waves in water

Answer 8

depth change

Question 9

what causes refraction of wave

Answer 9

change in speed

Question 10

how does water wave passing over shallower region change it

Answer 10

• slow down
• wavelength decrease

Question 11

what causes diffraction

Answer 11

wave passes thru gap

Question 12

when is diffraction more pronounced

Answer 12

when size of gap and wavelength similar

Question 13

impact of wavelength on diffraction

Answer 13

longer wavelengths diffract more

Question 14

impact of size of gap on diffraction

Answer 14

smaller gap means more diffraction

Question 15

where is angle of incidence/reflection measured from?

Answer 15

normal

Question 16

Characteristics of an optical image by a plane mirror

Answer 16

• same size
• same distance from mirror
• laterally inverted

Question 17

characteristics of image

Answer 17

• enlarged / same size / diminished
• upright / inverted
• real / virtual

Question 18

Relationship between angle of incidence and angle of reflection

Answer 18

Equal

Question 19

Define refraction

Answer 19

• change in direction of a light ray
• passing from one medium to another

Question 20

Define refraction

Answer 20

• change in direction of a light ray
• passing from one medium to another

Question 21

Define refractive index

Answer 21

Ratio of speeds of wave in 2 diff regions

Question 22

Equation for refractive index

Answer 22

Speed of light in substance / speed of light in vacuum

Question 23

What happens when light enters medium with higher refractive index

Answer 23

Bend toward normal

Question 24

What happens when light enters medium with higher refractive index

Answer 24

Bend toward normal

Question 25

Define critical angle

Answer 25

- angle of incidence - at which angle of refraction is 90 degrees and above - which all light is totally internally reflected

Question 26

Uses for total internal reflection

Answer 26

- endoscope (medicine) - optical fibre for communication

Question 27

What happens to image inside focal length of converging lens

Answer 27

- enlarged - virtual - upright

Question 28

What happens to image inside focal length of converging lens

Answer 28

- enlarged - virtual - upright

Question 29

What happens to image outside focal length of converging lens

Answer 29

- diminished - inverted - real

Question 30

What happens to image at principal focus of converging lens

Answer 30

No image formed

Question 31

Colours of visible spectrum in order of frequency (low to high) Order of wavelength (low to high)

Answer 31

red orange yellow green blue indigo violet violet indigo blue green yellow orange red

Question 32

Which light is bent most in a prism and why

Answer 32

Violet as it has the greatest changes in speed

Question 33

Main regions of EM spectrum in order of frequency (low to high) In order of wavelength (short to long)

Answer 33

radio, microwave, infrared, visible, ultraviolet, x-ray, gamma gamma, x-ray, ultraviolet, visible, infrared, microwave, radio

Question 34

Speed of EM waves in vacuum vs air

Answer 34

3.0*10^8 m/s Approx same in air

Question 35

Applications of radio waves

Answer 35

- radio and television transmissions - radar

Question 36

Applications of microwaves

Answer 36

- satellite television - mobile (cell) phone - microwave ovens

Question 37

Applications of infrared

Answer 37

- remote controllers for televisions - thermal imaging

Question 38

Applications of visible light

Answer 38

- vision - photography

Question 39

Applications of ultraviolet

Answer 39

- detecting fake bank notes

Question 40

Applications of x-rays

Answer 40

- medical scanning - security scanners

Question 41

Applications of gamma rays

Answer 41

- detection of cancer - treatment of cancer

Question 42

Harmful effects of excessive exposure to ultraviolet radiation

Answer 42

- damage to surface cells and eyes - leads to skin cancer and eye conditions

Question 43

Describe harmful effects of x-rays and gamma rays

Answer 43

- mutation or damage to cells in body

Question 44

How is sound produced

Answer 44

Vibrating sources

Question 45

Describe the longitudinal nature of sound waves in air

Answer 45

Series of compressions and rarefractions

Question 46

Describe what is meant by compressions

Answer 46

Regions of higher pressure due to particles being closer together

Question 47

Describe what is meant by rarefractions

Answer 47

Regions of lower pressure due to particles being spread further apart

Question 48

Is medium needed to transmit sound waves?

Answer 48

Yes

Question 49

Method for determining speed of sound in air

Answer 49

1. Measure large distance in straight line. Two people stand this distance apart 2. First person produces loud noise at same time as making visible action 3. Second person starts stopwatch when see first person move, stop stopwatch when hear sound

Question 50

Relative speeds of sound in states of matter in order of decreasing speed

Answer 50

Solids, liquids, gases

Question 51

How does amplitude affect sound

Answer 51

Changes loudness

Question 52

How does change in frequency affect sound waves

Answer 52

Pitch

Question 53

Describe what is meant by an echo

Answer 53

The reflection of a sound wave

Question 54

Define ultrasound

Answer 54

Sound with a frequency higher than 20kHz