General Waves (inc. ripple tank RP) - Paper 1

Question 1

What do waves transfer?

Answer 1

Energy (and information)

Not matter
Waves do not transfer matter

Question 2

Waves transfer energy in which direction?

Answer 2

The one they are travelling in

Question 3

What is meant by the amplitude of a wave?

Answer 3

Its displacement from the rest position (to a crest or trough)

Question 4

What is meant by a wavelength?

Answer 4

Length of a full cycle of a wave
(from crest to crest or compression to compression)

Question 5

What is meant by wave frequency?

Answer 5

The number of complete waves that pass a given point in one second

Question 6

What is frequency measured in?

Answer 6

Hertz (Hz)

waves per second

Question 7

1Hz means how many waves per second?

Answer 7

1

Question 8

2Hz means how many waves per second?

Answer 8

2

Question 9

2Hz means how many waves in one minute?

Answer 9

120

Question 10

1Hz means how many waves in one minute?

Answer 10

60

Question 11

What is meant by the period of a wave?

Answer 11

The time it takes for one full wave cycle (usually measured in seconds)

Question 12

What is the period of a wave usually measured in?

Answer 12

Seconds (s)

Question 13

What is the relationship between wave frequency and wave period?

Answer 13

Inversely proportional

Something = 1 over the other thing

Period = 1 / freq
Freq = 1 / period

Question 14

What is the difference between longitudinal and transverse waves?

Answer 14

Transverse - oscillations are perpendicular to the direction of travel
Longitudinal - oscillations are parallel to the direction of wave travel

Question 15

Oscillations are parallel to the direction of wave travel in which type of wave?

Answer 15

Longitudinal

Question 16

Oscillations are perpendicular to the direction of wave travel in which type of wave?

Answer 16

Transverse

Question 17

Give examples of transverse waves

Answer 17

EM
Seismic S waves
Water ripples

TransversEM

Question 18

Water ripples are an example of which type of wave

Answer 18

Transverse

Oscilllations occur perpendicular to the direction of wave travel

Question 19

Give examples of longitudinal waves

Answer 19

Seismic P waves
Sound

Question 20

Which wave do you get if you push the end of a spring?

Answer 20

A longitudinal wave

With compressions and rarefactions

Question 21

What is the opposite of a compression?

Answer 21

A rarefaction

Rarefaction - area of lower particle density and thus low pressure

Question 22

What is a rarefaction?

Answer 22

An area of lower particle density (and thus low pressure) in a longitudinal wave

Question 23

What is a compression?

Answer 23

An area of higher particle density (and thus high pressure) in a longitudinal wave

Question 24

Give two equations for wave speed

Answer 24

wave speed = distance / time
(v = x / t)
wave speed = freq x wavelength
(v = fλ)

“v equals f lambda”
V refers to waVe speed

Question 25

Give the equation linking wave speed and frequency

Answer 25

v = fλ wave speed = freq x wavelength | This means that wave speed and freq are directly proportional ## Footnote "v equals f lambda" V refers to waVe speed

Question 26

What does lambda (λ) refer to?

Answer 26

Wavelength

Question 27

Give the symbol for wavelength used in equations

Answer 27

λ Lambda

Question 28

Name the practical for measuring waves

Answer 28

Ripple Tank

Question 29

What is the aim of the ripple tank practical?

Answer 29

To calculate wavespeed by measuring frequency and wavelength of waves

Question 30

What is the independent variable in the ripple tank practical?

Answer 30

Frequency | I Can't Do Much Independent Change ## Footnote It's easier to change the freqency of the wave because it's directly controlled by adjusting the motor's speed Whereas, the DV, wavelength, is influenced by the depth of the water

Question 31

How do we change the independent variable of the ripple tank practical?

Answer 31

IV - Frequency Adjusting the speed of the motor which controls the how many waves the dipper produces

Question 32

How do we change the frequency of the waves in the ripple tank practical?

Answer 32

Adjusting the speed of the motor which controls the how many waves the dipper produces

Question 33

Name a control variable for the ripple tank practical

Answer 33

Depth of the water | This may affect the wavelength of the water ripples

Question 34

How would you set up the wave speed experiment?

Answer 34

Place a **shallow glass ripple** tank above a blank piece of **paper** **Half fill** the tank with water Place a **dipper**, attached to a **motor and power source**, so that it **just touches the water surface** Turn on **a strobe light above the tank** so that the waves can be seen underneath the tank on the paper **Adjust the frequency of the strobe light** until the waves beneath appear stationary

Question 35

How would you measure wavelength in the wave speed experiment?

Answer 35

Use a **ruler** to measure the **length of 10 complete waves** shown on the piece of paper **Divide this number by 10** to determine 1 wavelength

Question 36

How would you determine frequency in the wave speed experiment?

Answer 36

**Turn strobe light off** **Count the number of waves** reaching the end of the ripple tank **in 10 seconds** **Divide** this number **by 10** to obtain frequency

Question 37

What should you change when repeating the wave speed experiment?

Answer 37

The frequency of the waves by adjusting the speed of the motor controlling the dipper that creates the waves (You will also need to adjust the frequency of the strobe light)

Question 38

Despite repeating the ripple tank experiement with different wave frequencies, when calculating wave speed from v=fλ, why will wave speed remain constant?

Answer 38

Wave speed is directly linked to depth of water so, providing this is controlled, wavelength will decrease as frequency increases (because v=fλ shows them to be inversely proportional)