Edexcel ScienceiGCSE Physics

Q.Sound2019-2020

Name:________________Physics Teacher:______________

House CG Test Score

Year 11

Specification Checklist

3.01 use the following units: degree (°), hertz (Hz), metre (m), metre/second (m/s) and second (s)

3.02 explain the difference between longitudinal and transverse waves 

3.03 know the definitions of amplitude, wavefront, frequency, wavelength and period of a wave

3.04 know that waves transfer energy and information without transferring matter

3.06 use the relationship between frequency and time period:

time period = 1 ÷ frequency

T=1f

3.07 use the above relationships in different contexts including sound waves and electromagnetic waves

3.09 explain that all waves can be reflected and refracted

3.08 explain why there is a change in the observed frequency and wavelength of a wave when its source is moving relative to an observer, and that this is known as the Doppler effect

3.23 know that sound waves are longitudinal waves which can be reflected and refracted

3.24 know that the frequency range for human hearing is 20–20 000 Hz

3.25 practical: investigate the speed of sound in air

3.26 understand how an oscilloscope and microphone can be used to display a sound wave

3.27 practical: investigate the frequency of a sound wave using an oscilloscope

3.28 understand how the pitch of a sound relates to the frequency of vibration of the source

3.29 understand how the loudness of a sound relates to the amplitude of vibration of the source

Sound – Science (Physics) 2

Key Words

Key Word Image Definition

Amplitude The height of the wave from midpoint to peak.

Doppler Effect An increase (or decrease) in the frequency of a wave as the source and observer move towards (or away from) each other.

Frequency The amount of complete waves passing a point every second.

Hertz The unit for frequency. [Hz]

Longitudinal A wave that oscillates parallel to the direction of energy transfer.

Medium The substance a wave travels through.

Microphone An instrument for converting sound waves into electrical energy.

Oscillation A vibration.

Oscilloscope A device for viewing oscillations (e.g. sound waves) by a display on a screen.

Parallel In the same direction as.

Pitch The degree of highness or lowness of a tone.

Time Period The time taken for one complete wave to pass.

Transverse A wave that oscillates perpendicular to the direction of energy transfer.

Vacuum A space with no particles at all.

Wavelength The distance from peak to peak.

1: The Speed of Sound

Sound – Science (Physics) 3

Knowledge and Understanding Quiz

Use the knowledge you have gained since Shell to answer the following questions.

1. An object with a mass of 500g is traveling at 6m/s. What is the momentum of the object?

………………….. (3)

2. State Hooke’s Law

…………………………………………………………………………………………………………………………………………………………………………………… (1)

3. What is a vector quantity?

…………………………………………………………………………………………

………………………………………………………………………………………… (1)

4. What happens in the nucleus when beta decay is emitted?

…………………………………………………………………………………………

………………………………………………………………………………………… (2)

5. What is the definition of a transverse wave?

…………………………………………………………………………………………

………………………………………………………………………………………… (2)

6. Sketch the I-V curve for a light bulb in the space below.

(3)

Score [ /12]

Sound – Science (Physics) 4

Learning Outcomes:

1. Describe sound as a longitudinal wave that requires a medium 2. Describe an experiment to measure the speed of sound in air 3. Identify ways to improve your investigation and discuss how it could be improved

The two different types of waves.

Key Ideas

1. The two different type of waves are transverse and longitudinal. 2. Sound waves are longitudinal waves. 3. Longitudinal waves: The oscillation of the wave is parallel to the direction of energy

transfer. 4. All waves transfer energy and information. 5. It is important to know how to label and define the amplitude and the wavelength. 6. Sound waves need a medium to travel in and therefore sound cannot travel in a

vacuum.

Sound – Science (Physics) 5

Q1: Measuring the Speed of Sound in Air

In this investigation you are going to attempt to measure thespeed of sound as a class.

The method for this investigation comes up as a very common triple exam question!

What two quantities do we have to measure in order to calculate speed?

1.

2.

What equation would we then use to calculate sound?

Note: Both methods below are valid for this investigation. Your teacher will let you know which one you should be attempting.

Sound – Science (Physics) 6

Health and Safety Check!

Make loud noise away from ears to protect ear drum

Method 1 [Light vs. Sound]

1. Nominate 2 people walk to the far end of the playing field. [At least 100m]

a. Person 1 will measure the distance walked using a trundle wheel and will be responsible for lowering the trundle wheel. (visual signal)

b. Person 2 will be responsible for creating the sound. (audio signal)

2. All other members of the group will remain at the starting point with stopwatches.

3. Person 1 and 2 will then proceed to create their visual and audio signal at the same time.

4. Those with stopwatches will start the stop watch when they see the visual signal. (trundle wheel being lowered)

5. Those with stopwatches will stop the stop watch when they hear the audio signal. (bang from pot and stick)

6. Repeat investigation.7. Find the mean (average) of your results

for time.8. Use this value to calculate the speed

of sound using the equation: s=dt

Method 2 [Echo]

1. All members of the group should stand at least 50m away from a large wall. This should be measured with a trundle wheel.

2. Nominate 1 person to be responsible for creating an audio signal.

3. All other members of the group will have stopwatches.

4. Person 1 will then proceed to create audio signal.

5. Those with stopwatches will start the stop watch when they hear the audio signal that is created.

6. Those with stopwatches will stop the stop watch when they hear the echo of audio signal (reflected off the large wall)

7. Repeat investigation8. Find the mean (average) of your results

for time9. Use this value to calculate the speed

of sound using the equation: s=dt10. KEY: The distance travelled by the

sound will be double the distance between the group and the wall.

Results

What was the distance that the sound travelled in your investigation? ……………………… m

Record your own time results below:

My Results

Time (s) Average Time (s)

1 2 3

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GROUP RESULTS

Student Number Average Time (s)

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

Group Average Time:

Sound – Science (Physics) 8

Conclusions Use your group results/experience to answer the questions below.

1. Calculate your investigation value for the Speed of Sound

……………………m/s2. The accepted value for the speed of sound is 340 m/s

How do your results compare to this value?

………………………………………………………………………………………………………

………………………………………………………………………………………………………

3. Percentage error is measure of how far off your results are from the actual value. It is found using the following formula:

percentageerror=investigation value−actual valueactual value

×100

Calculate the % error in your results.

……………………%4. In most cases, the speed of sound measured in the investigation is smaller than the

actual value. Can you explain, with reference to your measurements, why this might be?

………………………………………………………………………………………………………

………………………………………………………………………………………………………

5. What changes could you make to this investigation that would likely give you a more

accurate set of results (closer to the true value)?

Change 1:

………………………………………………………………………………………………………

………………………………………………………………………………………………………

Change 2:

………………………………………………………………………………………………………

………………………………………………………………………………………………………

Sound – Science (Physics) 9

Worksheet – The Speed of Sound

Sound Travels at different speeds in different mediums. This is displayed in the bar chart below.

1. Which materials in the bar chart are solids, liquids and gases? [3]

Solids …………………………………………………………………………………………

Liquids ………………………………………………………………………………………..

Gases …………………………………………………………………………………………

2. In which material does sound travel fastest? [1] …………………….

3. In which material does sound travel slowest? [1] …………………….

4. Use your answers to questions 1-3 to complete the sentences below: [3]

The speed of sound, like all waves, depends on the _________________ through which

it travels. Sound travels fastest in ______________ (solids, liquids, gases) and slowest

in ______________.

5. You see a bolt of lightning and 4 s later we hear the thunderclap. If the speed of sound in air is 340 m/s, how far away is the lightning? [3]

…………………..

6. How many seconds will it take an echo to reach your ears if you yell toward a mountain 82 m away? [3]

…………………..7. You look up and see a helicopter pass directly overhead. 3.10s later you hear the sound

of the engine. How high was the helicopter flying? [3]

Sound – Science (Physics) 10

…………………..

8. Navy ships use sonar (sound navigation and ranging) to detect submarines. A sound pulse sent by the ship reflects off the submarine. If the submarine is 2.2 km away from the ship, and the speed of sound in seawater is 1400 m/s, how long will it take the sound pulse to travel out and back? [3]

…………………..

9. A person is listening with his ear against the rail for an oncoming train. A train blows a whistle when it is 1.65 km away,

a. How long will it take him to hear the sound of the whistle? (The speed of sound in steel is 5200 m/s.) [3]

…………………..

b. How long would it take his friend who is standing nearby to hear the same whistle? [3]

…………………..

10. If a ship captain sounds a foghorn toward an iceberg and hears the echo 4.6 s later, how far away is the iceberg? [3]

…………………..Score [ /29]

2: Displaying Sound

Sound – Science (Physics) 11

Knowledge and Understanding Quiz

Use the knowledge you have gained since Shell to answer the following questions.

1. Name the two forces acting on a parachute jumper as they fall through the sky.

……………………………………………………………… (2)

2. What is the law of conservation of energy?

…………………………………………………………………………………………………………………………………………………………………………………… (2)

3. Planet Y orbits a star with an orbital speed of 83.5 km/s. If it takes the plant 287 days to orbit the star, what must its orbital radius be?

………………….. (3)

4. What are the three methods of heat transfer?

…………………………………………………………………………………………

………………………………………………………………………………………… (3)

5. Sketch in the space below a circuit which would allows you to obtain results to plot

the I-V curve for a fixed resistor.

(4)

Score [ /14]

Learning Outcomes:

1. Name the equipment used to display sound waves.

Sound – Science (Physics) 12

2. Use an oscilloscope to show sound waves with different pitches and volumes.

3. Describe the effects of pitch and volume on the amplitude and time period of a sound wave.

Displaying Sound and Terminology

Key Ideas

1. We observe sound waves using and Oscilloscope.2. While sound waves appear transverse on the oscilloscope display, remember that

sound waves are longitudinal. 3. The time period of the sound wave on the oscilloscope is the distance from peak to

peak (or trough to trough).4. The distance from the equilibrium of the wave to the peak is the amplitude. 5. The range of human hearing is 20à20 000 Hz.

Q2: Observing Sound on an Oscilloscope

Sound – Science (Physics) 13

Health and Safety Check!

I will handle electrical components with care and report any equipmentthat seems damaged

In this investigation, you are going to be observing howthe image on an oscilloscope changes when the pitch and volume of the input sound is changed.

Your teacher is going to show you how to set up an oscilloscope. Use the space below to note down how to set up the oscilloscope.

Setting up the oscilloscope.

You may wish you annotate the picture to remind yourself of what the different contols do.

On the diagram below note down what the axes represent in an oscilloscope trace.

Sound – Science (Physics) 14

The method is written in the questions and will be underlined so it is vital that you work methodically through these.

1. Connect your oscilloscope to a signal generator and set it up so that you can clearly see the sound wave on the oscilloscope screen. [Please ask your teacher if you are stuck!]

2. Set your signal generator to emit a low pitched sound. Sketch below what you can see on your oscilloscope.

3. Now increase the pitch of the sound emitted by your signal generator. Do not change the time base on your oscilloscope. Sketch below what you can see on now your oscilloscope now.

4. What feature of your oscilloscope trace is the time period?

………………………………………………………………………………………………………

………………………………………………………………………………………………………

5. How did the time period change when you increased the pitch of the sound?

………………………………………………………………………………………………………

………………………………………………………………………………………………………

………………………………………………………………………………………………………

6. Did any feature of the oscilloscope trace stay the same?

………………………………………………………………………………………………………

………………………………………………………………………………………………………

Sound – Science (Physics) 15

7. Set your signal generator to emit a loud sound Sketch below what you can see on your oscilloscope.

8. Now decrease the volume (loudness) of the sound emitted by your signal generator without changing the pitch. Sketch below what you can see on your oscilloscope now.

9. What feature of your oscilloscope trace is the amplitude?

………………………………………………………………………………………………………

………………………………………………………………………………………………………

10. How did the amplitude change when you increased the volume of the sound?

………………………………………………………………………………………………………

………………………………………………………………………………………………………

………………………………………………………………………………………………………

STRETCH: Below are some of the controls you use less commonly on the oscilloscope. Have a play around with them and see if you can describe what they do.

Control What does it do?

Position

Time Var.

Focus

Level

Sound – Science (Physics) 16

Worksheet – Pitch and Volume

1. Why can sound not travel through a vacuum? [1]

…………………………………………………………………………………………………….

…………………………………………………………………………………………………….

2. In which ways does sound behave like light? [2]

…………………………………………………………………………………………………….

…………………………………………………………………………………………………….

3. A sound wave travels to a wall and returns 0.5 s later.

a. What is the total distance travelled? (Speed of sound = 340 m/s) [2]

……………………

b. How far away is the wall? [1]

……………………

4. What can you say about the speed of sound compared with light? [1]

…………………………………………………………………………………………………….

5. What is a longitudinal wave? [2]

…………………………………………………………………………………………………….

…………………………………………………………………………………………………….

Sound – Science (Physics) 17

6. What is the range of human hearing? ………………………………………………………..

7. Here are 2 oscilloscope traces:

a. Which has the higher frequency? [1]

b. Which has the shorter wavelength? [1]

c. Which has the bigger amplitude? [1]

d. Describe how sound A would sound different to sound B. [2]

………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

8. On the oscilloscope screens below, add the traces you would expect to see for the sound described. [6]

Sound – Science (Physics) 18

[Score /23]

Sound – Science (Physics) 19

3: Measuring Frequency with an Oscilloscope

Knowledge and Understanding Quiz

Use the knowledge you have gained since Shell to answer the following questions.

1. Which heat transfer can occur in a vacuum?

……………………………………………………………… (1)

2. A radioactive source has a half life of 60 days. What will its activity be after 180 days if its current activity is 300 Bq?

………………….. (3)

3. What name is given to the point on an object trough which weight always acts?

………………………………………………………………………………………… (1)

4. On the longitudinal wave below, label the wavelength in two different places.

[2]

5. Sketch the shape of the orbit of a comet around the star in the space below.

Add a comet to your orbit and draw its tail.

(3)

Score [ /10]

Sound – Science (Physics) 20

Learning Outcomes:

1. Define the time period, time base and frequency of a wave.2. Measure the time period of a wave using the correct time base.3. Calculate the frequency of a sound wave using the equation:

f= 1T

Time Period, Time Base and Frequency

Prefix Value

Mega [M]

Kilo [k]

Centi [c]

Milli [m]

Micro [μ]

Nano [n]

Key Ideas

1. Frequency and time period are linked in the equation

Frequency= 1Time Period

2. Frequency is a defined as the number of complete waves per second. 3. Time period is a defined as the time taken for one complete wave to pass. 4. The time period on an oscilloscope is found by measuring the distance from peak to

peak.5. The time base is the distance each square on the x-axis represents.

Sound – Science (Physics) 21

Worked Examples

1. What is frequency of a wave with a time period of 6s?

2. What is frequency of a wave with a time period of 5.5 ns?

3. Look at the oscilloscope trace above. The time base on the oscilloscope is 3ms. a. What is the time period of the sound wave?

b. What is the frequency of the sound wave?

Sound – Science (Physics) 22

Worksheet – Time Period and Frequency Calculations

Complete the questions below using the equation you have just learnt. You must show all of your working [equation, substitution, solution and units].

1. What is the period of a pendulum that has a frequency of 0.5 Hz?

…………………..

2. The frequency of a vibrating object is 15 Hz. What is the time period of this vibration?

…………………..

3. What is the frequency of long wave radio signal that has a period of 1 millisecond?

…………………..

4. An ocean wave has been observed with a period of 16 seconds. What is the frequency of this wave?

…………………..

5.

6.

7.

Sound – Science (Physics) 23

8.

9.

10.

STRETCH: Some more questions to consider.

1. Why do string telephones work?

…………………………………………………………………………………………………….

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2. Why are helicopters so noisy?

…………………………………………………………………………………………………….

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…………………………………………………………………………………………………….

Sound – Science (Physics) 24

Q3: Measuring Frequency with an Oscilloscope

In this investigation you are going to use an oscilloscope to measure the frequency of a signal.

An oscilloscope displays time on the x-axis.

On the wave below mark one the distance of 1 time period:

This oscilloscope has a time base of 2ms. This means that one square across the x-axis equals 2ms. Using this information can you work out the time period of the wave?

Time Period = …………………… s

Use this time period to calculate the frequency of the wave:

Frequency = ……………………

Method

1. Connect the signal generator to the oscilloscope. 2. Alter the time-base on your oscilloscope until you can clearly see the waveform.3. Note down the time base you are using!4. Measure the time period of your

wave.5. Calculate the frequency of your

wave. 6. Repeat for a number of different

input frequencies.

Sound – Science (Physics) 25

Health and Safety Check!

I will handle electrical components with care and report any equipmentthat seems damaged

Results

Signal 1

Time Base Used

Time Period [s]

Frequency [Hz]

Signal 2

Time Base Used

Time Period [s]

Frequency [Hz]

Signal 3

Time Base Used

Time Period [s]

Frequency [Hz]

Signal 4

Time Base Used

Time Period [s]

Frequency [Hz]

4: The Doppler Effect

Sound – Science (Physics) 26

Knowledge and Understanding QuizUse the knowledge you have gained in the previous few lessons to answer the following questions:

1. Describe the relationship between temperature and resistance for a thermistor.

…………………………………………………………………………………………

………………………………………………………………………………………… (2)

2. What is meant by the word ‘irradiation'

………………………………………………………………………………………… (1)

3. A wave is travelling at 460m/s and has a frequency of 5kHz. What is the wavelength

of the wave?

………………….. (3)

4. The oscilloscope display below has a time base of 5ms. What is the:

a. Time period

b. Frequency

(4)

Score [ /10]

Learning Outcomes:

Sound – Science (Physics) 27

1. State that when an object emitting sound is moving relative to the observer, there is a change in its frequency

2. Describe the Doppler Effect3. Explain how the frequency of a wave changes if it is moving away or towards

the observer

The Doppler Effect

Key Ideas

1. When a sound emitting object is not moving the sound waves we detect have a constant frequency and wavelength.

2. If the object is moving towards you the wavefronts get compressed so the sound increases in frequency (sounds higher pitched than when stationary).

3. If the object is moving away from you the wavefronts get stretched out so the sound decreases in frequency (sounds lower pitched than when stationary).

4. This apparent change in frequency is called the Doppler Effect.5. The Doppler effect can happen to all types of waves (including light and sound).

Sound – Science (Physics) 28

Worksheet – The Doppler Effect Score [ /14]For Questions 1-6 circle or underline the correct answer.

1. When an automobile moves towards a listener, the sound of its horn seems relatively [1]

a. Low pitched (low frequency)

b. High Pitched (high frequency)

c. Normal (no change in frequency)

2. When the automobile moves away from the listener, its horn seems [1]

a. Low pitched (low frequency)

b. High pitched (high frequency)

c. Normal (no change in frequency)

3. The change in pitch of the Doppler effect is due to changes in [1]

a. wave speed

b. wave frequency

4. True / False: [1]If the object stays still, but the observer moves, the Doppler effect is still observed.

5. True / False: [1]A moving wave source does not affect the frequency of the wave encountered by the observer.

6. True / False: [1]A higher frequency results when a wave source moves towards an observer.

7. Two fire trucks with sirens on speed towards and away from an observer as shown below.

a. Which truck produces a higher than normal siren frequency? [1]

b. Which truck produces a lower than normal siren frequency? [1]

Sound – Science (Physics) 29

A B

STRETCH: The following questions will ask you to take what you have learnt about sound and apply the concepts to light.

8. List the colors of the visible light spectrum in order of lowest to highest frequency. [2]

9. When galaxies move away from us they appear to have a “red shift” in color. Explain

why this happens. [3]

……………………………………………………………………………………………

……………………………………………………………………………………………

……………………………………………………………………………………………

10. What color do galaxies appear if they are moving towards us? [1]

……………………………………………………………………………………………

11. Define 2 other real world applications of the Doppler effect? Draw a diagram if you can!

[You may use your computer to help you here!]

Application 1:

……………………………………………………………………………………………

……………………………………………………………………………………………

……………………………………………………………………………………………

……………………………………………………………………………………………

Application 2:

……………………………………………………………………………………………

……………………………………………………………………………………………

……………………………………………………………………………………………

……………………………………………………………………………………………

Sound – Science (Physics) 30

Stretch Activity – How Oscilloscopes Work

Oscilloscope screens are actually just Cathode Ray Tubes. They very cleverly manipulate a ray of electrons to create the display that you observe. Take a look at the video below. Use the box to make notes or sketches as you are watching.

https://www.youtube.com/watch?v=7s5v8TFBaRk

Summarise what you have learnt in the space below:

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Sound – Science (Physics) 31

Stretch Worksheet – Communication Under the Sea

In this stetch activity you are going to research the communication skills of underwater mammals. Use you computer to figure out the scientific answers to the questions below.

How do mammals communicate underwater? How does this communication compare to that of

land mammals? Why does underwater communication need to be

different from land communication?

[Stuck: Try visiting the websites below to get you started!]

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https://www.livescience.com/37232-could-humans-and-dolphins-ever-talk-to-each-other.html

https://www.nationalgeographic.com.au/science/blue-whales-and-communication.aspx

This is just awesome: https://phys.org/news/2017-05-scientists-probe-dolphin-intelligence-interactive.html

Sound – Science (Physics) 32

Sound

Past Paper Questions

Q1. This question is about sound waves.

(a) Sound waves are

(1)

   A    electromagnetic waves

   B    ionising radiation

   C    longitudinal waves

Sound – Science (Physics) 33

   D    transverse waves

(b) Describe an experiment to measure the speed of sound in air.

(5)

      .............................................................................................................................................

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(c) The speed of sound in air is different for different heights above sea level.

The graph shows how the speed of sound varies with height.

Sound – Science (Physics) 34

(i) Use the graph to estimate the speed of sound in air 6000 m above sea level.

(1)

Speed = ........................................................... m/s

(ii) Describe the pattern shown by the graph.

(2)

      .............................................................................................................................................

      .............................................................................................................................................

      .............................................................................................................................................

      .............................................................................................................................................

      

(iii) Some aeroplanes can travel faster than the speed of sound.

When an aeroplane travels faster than the speed of sound it causes a shock wave.

Sound – Science (Physics) 35

People on the ground hear this shock wave as a sonic boom.

A student says

Do you agree with the student?

Explain why.

(2)

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(Total for question = 11 marks)

Sound – Science (Physics) 36

Q2. A microphone is connected to an oscilloscope to display a sound wave.

The diagram shows the trace on the oscilloscope screen.

The oscilloscope settings are:

Y direction: 1 square = 1 V

X direction: 1 square = 0.001 s

(a) (i) How many time periods are shown on the trace?

(1)

      .............................................................................................................................................

(ii) What is the frequency of the sound wave?

(2)

Frequency = ........................................................... Hz

Sound – Science (Physics) 37

(b) On the grid below, sketch the trace of a sound wave with a smaller amplitude anda higher frequency than the wave shown by the dotted line.

(2)

(Total for question = 5 marks)

Sound – Science (Physics) 38

Q3. A signal generator produces sounds from a loudspeaker.

(a)  (i)  Which property of the sound wave should be increased in order to make the sound louder?

(1)

   A    amplitude

   B    frequency

   C    speed

   D    wavelength

(ii)  Which property of the sound wave should be increased in order to make a higher pitched sound?

(1)

   A    amplitude

   B    frequency

   C    speed

   D    wavelength

(b)  Sound waves travel as longitudinal waves.

Other waves are transverse.

(i)  Give an example of a transverse wave.

(1)

.............................................................................................................................................

(ii)  Describe how the vibrations of longitudinal waves and transverse waves differ.

(2)

.............................................................................................................................................

.............................................................................................................................................

.............................................................................................................................................

.............................................................................................................................................

 

(Total for question = 5 marks)

Sound – Science (Physics) 39

Q4. A student investigates how air vibrates in a plastic pipe.

She blocks one end of the pipe and blows across the other end.

The pipe emits a sound with a steady pitch.

The student uses a microphone to monitor the sound.

(a)  Explain the meaning of the pitch of a sound.

(2)

.............................................................................................................................................

.............................................................................................................................................

.............................................................................................................................................

(b)  The student measures the length of the pipe and the frequency of the microphone signal for two different lengths of pipe.

(i)  Name two instruments that she will need for these measurements.

(2)

1 ..........................................................................................................................................

2 ..........................................................................................................................................

(ii)  Name the dependent and independent variables in her investigation.

(2)

dependent variable

.............................................................................................................................................

independent variable

.............................................................................................................................................

Sound – Science (Physics) 40

(c)  The student collects this data.

Suggest three ways to improve this investigation.

(3)

1 ..........................................................................................................................................

.............................................................................................................................................

2 ..........................................................................................................................................

.............................................................................................................................................

3 ..........................................................................................................................................

.............................................................................................................................................

 

(Total for question = 9 marks)

Sound – Science (Physics) 41

Sound

Spec Point Notes

Sound Specification Notes

3.01 use the following units: degree (°), hertz (Hz), metre (m), metre/second (m/s) and second (s)

Sound – Science (Physics) 42

3.02 explain the difference between longitudinal and transverse waves 

3.04 know that waves transfer energy and information without transferring matter

3.03 know the definitions of amplitude, wavefront, frequency, wavelength and period of a wave

Sound – Science (Physics) 43

3.06 use the relationship between frequency and time period:

time period = 1 ÷ frequency

Sound – Science (Physics) 44

T=1f

3.07 use the above relationships in different contexts including sound waves and electromagnetic waves

3.08 explain why there is a change in the observed frequency and wavelength of a wave when its source is moving relative to an observer, and that this is known as the Doppler effect

3.09 explain that all waves can be reflected and refracted

Sound – Science (Physics) 45

3.23 know that sound waves are longitudinal waves which can be reflected and refracted

3.24 know that the frequency range for human hearing is 20–20 000 Hz

3.25 practical: investigate the speed of sound in air

Please see page 6 of this booklet for the full investigation.

3.26 understand how an oscilloscope and microphone can be used to display a sound wave

Sound – Science (Physics) 46

3.27 practical: investigate the frequency of a sound wave using an oscilloscope

Please see page 23 of this booklet for the full investigation.

3.28 understand how the pitch of a sound relates to the frequency of vibration of the source

Sound – Science (Physics) 47

3.29 understand how the loudness of a sound relates to the amplitude of vibration of the source

Sound – Science (Physics) 48