level 3 waves

Question 1

Types of waves

Answer 1

transverse (light) and longitudinal (sound)

Question 2

Longitudinal waves

Answer 2

particles oscillate in the same direction as the wave move.

Question 3

V term in the wave equation

Answer 3

Wave speed (ms-1)
either light or sound

Question 4

f term in the wave equation

Answer 4

equation
Frequency (Hz)

Question 5

λ term in the wave equation

Answer 5

Wavelength (m)

Question 6

Diffraction

Answer 6

The bending of waves as they pass through a gap or slit

Question 7

Amplitude

Answer 7

The energy carried in a wave

Question 8

Interference

Answer 8

When 2 or more waves meet in some medium. Interference occurs and a resultant wave form is created

Question 9

Transverse waves

Answer 9

particles are moving at 90 to the direction of wave movement

Question 10

The wave equation

Answer 10

v=fλ

Question 11

Constructive Interference

Answer 11

Constructive Interference occurs when 2 waves meet in phase (crest meets crest or through meets through) resulting in a greater amplitude.

Question 12

Destructive interference

Answer 12

Destructive interference occurs when 2 waves meet out of phase (crest meets through) resulting in reduced amplitude.

Question 13

The double slit equation when θ is less than 10

Answer 13

nλ=dx/L

Question 14

d in the double slit equation when θ is less than 10

Answer 14

Slit separation (m)

Question 15

x in the double slit equation when θ is less than 10

Answer 15

Fringe separation (m)

Question 16

L in the double slit equation when θ is less than 10

Answer 16

Length from slit to screen (m)

Question 17

The double slit equation when θ is greater than 10

Answer 17

nλ=dsinθ

Question 18

What would happen if slit separation increased?

Answer 18

If wavelength and screen distance (L) stay constant, but slit separation (d) increases the distance between the adjacent bright spots reduces and the bright fringes get closer together.

Question 19

What would happen if the screen is moved further away?

Answer 19

If wavelength and slit separation (d) stay constant and screen (L) moves further away then the distance between bright will decrease Fringes get closer together.

Question 20

What would happen if Lazar changes from red to violet light?

Answer 20

Red diffracts more than violet. When d and L stay constant a change to violet means the wavelength has decreased. This means theta decreases so the pattern becomes closer together.

Question 21

What would happen more slits are added?

Answer 21

More slits means antinodes are brighter. Because there are more sources of light the antinodes are brighter. More waves means more chance of destructive interference. Brighter antinodes mean nodes are clearer and more defined.

Question 22

What happens when white light is shone through slits?

Answer 22

White light is made of ROYGBIV, all these have a different wave length. Wavelength then diffracts at different angles. Each wavelength interacts differently with the slit. This results in the separation of white light into its constituent colours, a phenomenon known as dispersion.

Question 23

What happens when the central bright spot is n=0?

Answer 23

This is where all waves meet in phase, constructive interference occurs and a antinode forms. This is the brightest antinode in the pattern.

Question 24

What must nmax always be?

Answer 24

Nmax must always be a whole number so you must round DOWN.

Question 25

How do you calculate the maximum number of fringes that can be used?

Answer 25

nmax = d/wavelength

Question 26

How are standing waves formed?

Answer 26

Standing waves are formed when a travelling wave encounters a boundary and is reflected back. Causes interference with the incoming reflected wave, which sets up the standing wave (appears stationary)

Question 27

What are the rules for standing waves?

Answer 27

Waves must have the same wavelength and frequency. Waves must be the same amplitude. Waves must be travelling in opposite directions.

Question 28

Standing wave boundaries: Fixed

Answer 28

Wave is reflected 180 out of phase. Causes destructive interference. Node is formed.

Question 29

Standing wave boundaries: Open

Answer 29

Wave is reflected back in phase. Causes constructive interference. Antinode is formed.

Question 30

Types of 'instruments' that form standing waves.

Answer 30

Fixed end. Open/Open end. Open closed end.

Question 31

What do fixed end standing waves look like?

Answer 31

Both ends are fixed causing Nodes to form and both ends.

Question 32

What is the fundamental wavelength equation?

Answer 32

wavelengthxfrequncy = 2xL

Question 33

What is the frequencies on harmonics equation?

Answer 33

fn = nFf

Question 34

What is fn in frequencies on harmonics equation?

Answer 34

Frequency of harmonic (Hz)

Question 35

What is different about the speed of sound on a string?

Answer 35

The speed of sound is not constant on a string. It can change due to; tension of the string, thickness of string (mass per metre).

Question 36

What is the equations for speed of sound on a string?

Answer 36

v= square root of T/m

Question 37

What is the unit for m in the equation for speed of sound on a string?

Answer 37

kgm-1

Question 38

What do open/Closed standing waves look like?

Answer 38

They have one closed/fixed end and one open end.

Question 39

What is the only harmonics that open/closed waves can form?

Answer 39

open/closed pipes can only form odd harmonics as they must end in a node and antinode.

Question 40

How do open/closed harmonics sound compared to fixed string or open/open pipes?

Answer 40

The sounds produced is less rich than fixed string or open/open pipes as less harmonics are able to form.

Question 41

What are two reasons wave speed can change in pipes?

Answer 41

Medium (eg water making sound travel faster)) and temperature (warmer air making sound travel faster)

Question 42

What is timbre affected by?

Answer 42

Shape of the instrument and material used to make instrument.