ScienceYear 8 Physics

Sound

Notes & Experiments

Name: ________________Teacher: ______________

YOU MUST KEEP THIS BOOK

MY UNDERSTANDING CHECKLIST

[INSERT SCHOOL LOGO HERE]

I can… Textbook page(s)

Before the Topic

After the Topic

Detecting SoundDescribe sound waves as vibrations 28State that all sound waves require a medium to travel through 28

Describe the effect that changing the amplitude and frequency has on the sound that we hear 30 – 31

Hearing SoundName the parts of the ear and give their role in hearing sound 32

Give the range of Human hearing and compare it to that of other animals 31

Use the speed of sound to determine distance using Echoes 34

Seeing SoundDescribe the frequency and time period of a wave -

Determine the time period of a sound wave using the time base of an oscilloscope -

Calculate the frequency of a sound wave using the time period -

Speed of SoundState that the speed of sound is 340m/s in air 28Describe and carry out an investigation to determine the speed of sound -

Explain changes that would improve accuracy of experimental results -

Stretch: Using OscilloscopesSet up an oscilloscope to show a sound wave in transverse form -

Explain the effect of changing the amplitude has on the sound wave shown on the oscilloscope. 30 - 31

Explain the effect that changing the frequency has on the sound wave shown on the oscilloscope.

30 - 31

MY SKILLS CHECKLIST

I can… Before the Topic After the TopicLabel a scientific diagramCalculate distance using EchoesInterpret the display on an oscilloscope.

KEY WORDS

Some of the key words and definitions are missing some information! Can you complete them?

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Key Word Image/Diagram DefinitionAmplitude

The maximum ________ moved by any point on a wave. It is measured from the middle of the wave to the _______ or _______

Frequency The number of ________ per _______

Transverse Wave

A wave in which the vibrations are ________ to the direction of travel.

Longitudinal Wave

A wave in which the vibrations are ________ to the direction of travel.

A part of the ear which vibrates at different speed depending on the ___________ of the sound.

Pitch A measure of how ______ or _______ a sound is. It is dependent on _____________

Volume A measure of how ______ or _______ a sound is. It is dependent on _____________

3

The area of variation between upper and lower limits on a particular scale.

Reflection When a wave hits a surface and then _________ back.

Loudspeaker A device that produces a __________ wave.

The time it takes for one complete wave to pass.

Oscilloscope A machine used to display waveforms.It measures _________ on the y-axis and ______ on the x-axis.

When a sound wave is reflected off a surface and heard again.

Speed of Sound

The speed that sound travels in air (a vacuum). It has the value _________ m/s.

4

Lesson 1: Detecting Sound

DEVELOPING Describe sound waves as vibrationsSECURE State that all sound waves require a medium to travel

throughEXTENDING Describe the effect that changing the amplitude and

frequency has on the sound that we hearSCIENTIFIC SKILLS Label a scientific diagram

Do Now: Knowledge and Understanding Quiz

1. Sketch and label an example of a transverse wave. [4]

2. Sketch and label an example of a longitudinal wave. [4]

3. Use your knowledge from the Light topic to fill in the blanks. [7]

In a Transverse wave the oscillations are _____________ to the direction of energy

transfer. An example of a Transverse wave is ______________.

In a Longitudinal wave the oscillations are _____________ to the direction of energy

transfer. An example of a Longitudinal wave is ______________.

In a Transverse wave we call the distance from peak to peak the ________________.

We measure this in ___________. The distance from the equilibrium to the peak (or

trough) is called the _________________.

Score [ /15]

5

Sound Waves

Sound waves are produced by objects that are _________.

All speakers have something that moves _____________ and _____________, or

_________.

This makes the air molecules vibrate which produces a ________ wave.

We hear sounds when these __________, travelling as sound waves reach our ears.

When the reach our ears, our __________ vibrates and this is how we detect sound.

Sound can only travel through a __________ such as solid, liquid or gas.

Sound cannot travel through a __________ because there are no air molecules to

__________.

In air, sound travels at ______ m/s.

Sound travels fastest in a ________, as the particles are _____ _______ together,

so the vibrations can be passed along faster than in a _______ or ______.

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Teacher Demo: Pitch and Volume

Sound waves can be viewed using an ____________.

It is important to be aware than sound waves are __________ waves, but when shown on the screen appear as _________ waves.

Your teacher will now demonstrate how the volume and pitch affect the sound output from the oscilloscope.

In the table below, make notes about what you hear during the demonstration,

Sound Wave Characteristic Oscilloscope Sketch Observation notes on the

sound

High Frequency

Low Frequency

Large Amplitude

Small Amplitude

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Volume and Pitch

Volume

On an oscilloscope trace, the loudness of a sound is shown by the _______ of the

wave. This is called the _________.

The larger the amplitude of the wave, the __________ the sound.

PitchOn an oscilloscope trace, the pitch of a sounds is shown by how many _______

there are. This is called the ___________.

The greater the number of waves across the oscilloscope trace, the ___________

the frequency and pitch.

8

SummaryOn the oscilloscope screens below, add the traces you would expect to see for the

sound described.

Redraw the sound wave below with the same pitch but double the volume.

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A loud sound has a large _________.

A high-pitched sound has a large number of ________ per second.

Worksheet: Pitch and Volume

Use the figure below to complete the following questions.

1. Which oscilloscope trace produces the loudest sound? _______

2. Which oscilloscope trace produces the quietest sound? _______

3. Which oscilloscope trace produces the highest pitch sound? _______

4. Which oscilloscope trace produces the lowest pitch sound?

5. Which oscilloscope trace has the lowest frequency? _______

6. Which oscilloscope trace has the smallest amplitude? _______

7. Here are 2 oscilloscope traces:

a. Which has the higher frequency?

b. Which has the bigger amplitude?

c. Describe how sound A would sound different to sound B.

…………………………………………………………………………………

…………………………………………………………………………………

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Lesson 1: Detecting Sound

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You may of heard of something called a sonic boom.

This is a loud “boom” sound which occurs when an object travels faster than the speed of sound. We say that the object is breaking the sound barrier.

Using the table below. Can you identify which objects are breaking the sound barrier causing a sonic boom?

Object Distance travelled (m)

Time taken (s)

Speed (m/s)

Fighter jet 1000 2

Boeing 747 1332 6

Bloodhound car 6000 13

Whip 52 0.14

Toy car 1.2 1.6

Lab chair 0.2 0.5

A speeding bullet 70 0.17

STRETCH

Answer:

Lesson 2: Hearing Sound

DEVELOPING Name the parts of the ear and give their role in hearing sound

SECURE Give the range of Human hearing and compare it to that of other animals

EXTENDING Use the speed of sound to determine distance using Echoes

SCIENTIFIC SKILLS Calculate distance using Echoes

Do Now: Knowledge and Understanding Quiz

1. A car is travelling at a constant speed of 6 m/s. How long will it take the car to travel 114m? [3]

……………………………………..

2. Draw a labelled diagram to state what is meant by the law of reflection? [4]

3. Add appropriate equipment to the following circuit to show how you would measure:

a. The current through the circuit b. The voltage across the lightbulbc. Explain how you would calculate the resistance of the light bulb

Detecting Sound

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……………………………………………

……………………………………………

……………………………………………

……………………………………………

……………………………………………

Use the diagrams above to fill in the missing words below. Some words can be used more than once.

When a sound is produced when ___________ travel through the air.

These __________ will eventually reach your ear where the _______ collect and direct the sound waves into your ____ _________.

The vibrations then travel along through your ____ _______ and collide with your ____ ________.

This cause the ear drum to _________ back and forward.

These vibrations are then passed onto the ___________ which are made up of three tiny bones.

The ossicles in turn vibrate and ________ the sound.

The sound is then passed onto the _________ which is a fluid filled tube with small ____ ______ on the surface which start to move.

As the hairs move, they send ________ signals along the auditory nerve to the brain.

The brain then interprets these sounds, and this is how we _____.

Teacher Demo: Range of Human Hearing

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BBC Teach Useful Video (here)

Extra YouTube Video: https://www.youtube.com/watch?v=RiVx5Lih_44

ossicles pinna amplifies ear drum vibrate cochlea vibrations ear canal hair cells

electrical hear

Your teacher is going to play you a range of frequencies.

The unit of frequency is ______________.

Make note of the lowest and highest frequency that you can hear in the table below

Range of Hearing in Animals

Below is a table showing the range of hearing for various animals. Use the table to answer the questions on the next page.

Worksheet: Range of Hearing in Animals

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Frequency (Hz)

Lowest

Highest

1. What is the range of hearing for Humans?

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

2. What is the range of hearing for Bats?

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

3. Which types of Animals can hear higher frequencies than Humans?

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

4. Which types of Animals can hear lower frequencies than Humans?

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

5. Which Animal(s) have the largest range of hearing? How can you tell this from the graph?

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

6. Which Animal(s) have the smallest range of hearing? How can you tell this from the graph?

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

7. Use the information in the graph to explain why Humans cannot hear “dog whistles”.

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

Volume of Sound

Sound levels are measured on a scale known as the ________   scale.

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The decibel scale is not like a ruler. Each increase of 10 dB increases the sound intensity by ____ times.

Too much noise can damage hearing. Exposure to 90 decibel sound levels for a long time can cause permanent hearing loss.

Complete

Background noise at home

At a concert - 1 metre from a loudspeaker

Normal talking

Whispering

Source of Sound Sound level in decibels

Cannot be heard 0

20

40

60

Noise pollution level 90

Pneumatic drill - 5 metres away 100

120

Gun shot 140

Science Skill: Using Echo’s to calculate distance

Your teacher is going to show you a short clip about Echo’s and echo location. In the space below can you explain your understanding of:

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1. what an echo is.

2. how Echolocation works

Impressive use of Echolocation Video: https://www.youtube.com/watch?v=fnH7AIwhpik

You may want to use a diagram to help you.

…………………………………………………………

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…………………………………………………………

…………………………………………………………

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Worked Example

A man stands near a cliff face and creates a sound. He hears the echo of that sound 2.5s later.

a. On the diagram add arrows to show the path of the sound wave.b. Calculate how far away the man is from the cliff face

Worksheet: Calculations with Echoes

For the following questions be aware that sound/ultrasound travels at 1500m/s in water, compared to 340m/s in air.

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Diagram:

?

Q1: Ultrasound and bats 

If it took 1 second for a bat to detect the ultrasound, how far away is the prey? [4]

…..………………………………………………………………………………

…………………………………………………………………………………..

Q2. Dolphins

A dolphin lets out a high pitch ultrasound call to locate her lost calf. She detects the ultrasound 0.85 seconds later. How far away is the calf? [4]

….…………………………………………………………………….

………………………………………………………………………..

A few moments later she calls again, this time she detects the ultrasound 0.95 seconds later. Is the calf getting closer or further away? [1]

………………………………………………………………………………………....

Q3. Ultrasound and ships [4]

An iceberg is 3,000 metres from a submarine. The submarine emits ultrasound. How long until the submarine detects the iceberg? 

……………………………………………………………………………………………

………………………………………………………………………………………………

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Match up the damage to the cause and treatment. You may wish to use the internet to help you.

STRETCH

Q4.

Lesson 3: Seeing Sound

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Match up the damage to the cause and treatment. You may wish to use the internet to help you.

DEVELOPING Describe the frequency and time period of a waveSECURE Determine the time period of a sound wave using the

time base of an oscilloscopeEXTENDING Calculate the frequency of a sound wave using the

time periodSCIENTIFIC SKILLS Interpret the display on an oscilloscope.

Do Now: Knowledge and Understanding Quiz

On the diagrams below draw a wave which has:

(a) A quieter sound(b) A higher pitch(c) A louder sound(d) A louder sound AND a lower pitch

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A

B

C

D

Frequency and Time Period

The time period (___) of a wave is the ______ it takes for one complete

wave to pass a fixed point.

It is measured in _____________ (s).

The frequency (____) of a wave is the number of _______ __________

which pass a fixed point per ___________.

It is measured in ____________ (Hz).

As we increase the frequency the time period gets smaller. They are in fact mathematically linked.

Frequency and Time Period are linked by the following equation:

frequency ( f )=

Which can be represented in the following equation triangle:

Worked Example

The frequency of a sound wave is 200 Hz. What is the Time Period of the wave?

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Worksheet: Frequency and Time Period

Use the Equation Triangle and the definitions of frequency and time period to answer the following questions.

1. A swing has a time period of 3 seconds. What is its frequency?

2. A bouncing basketball has a time period of 0.7 seconds. What is its frequency?

3. A TV has a refresh frequency of 60 Hz. What is its time period?

4. A clock ticks 3 times every 5 seconds. What is its frequency?

5. A man exercising can do 15 push-ups in 20 seconds. What is his frequency?

PEER MARKScore [ /15]: Next Steps:

Science Skill: Reading an Oscilloscope

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As we have seen already, an oscilloscope can be used to display sound waves.

It is important to remember that sound waves are ___________ waves, where the oscillations are ________ to the energy transfer.

However, when displayed on the oscilloscope screen they are shown as _________ waves.

Using the oscilloscope trace, we can calculate the frequency of a given sound wave.

See Boardworks animations: Looking at Sound Waves & online oscilloscope https://academo.org/demos/virtual-oscilloscope/

With help from you teacher label the following properties on the oscilloscope trace below.

a. One complete waveb. The amplitudec. The time period d. The time base

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Worked Example:

If the time base of the above wave is 0.1s. Calculate the frequency of the wave.

Worksheet: Oscilloscope Traces

For each of the oscilloscope traces below:

a. Mark one complete waveb. Label the time period c. Assuming the time base is 0.1s calculate the time period d. Calculate the frequency of the wave

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1

2

3

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1. Redraw the sound wave below with double the amplitude and twice the frequency.

2. Use the oscilloscope traces to measure the time period and then calculate the frequency of each sound.

STRETCH

Lesson 4: Speed of Sound

DEVELOPING State that the speed of sound is 340m/s in airSECURE Describe and carry out an investigation to determine

the speed of sound

EXTENDING Explain changes that would improve accuracy of experimental results

SCIENTIFIC SKILLS Calculate distance using Echoes

Do Now: Speed, Distance and Time Calculations

1. What is the equation linking speed, distance and time?

2. Can you put this into a triangle to help with rearranging the equation using the correct symbols.

3. If you move 50 meters in 10 seconds, what is your speed?

………………………

4. You arrive in my class 45 seconds after leaving Maths which is 90 meters away. How fast did you travel?

………………………

5. A plane travels 395,000 meters in 9000 seconds. What was its speed?

………………………

6. It takes Serine 0.25 hours to drive to school. Her route is 16 km long. What is Serine’s average speed on her drive to school (in m/s)?

………………………

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Which is faster: Sound or Light

Imagine you are out in a thunderstorm. Would you expect to hear the thunder or see the lightening first?

Prediction: ____________

Light travels much ________ than sound.

The speed of light is _________________ m/s, so it is almost a __________ times

faster than sound.

Therefore, during the thunderstorm; you immediately see the lightening, but it takes

a while for the thunder to reach you.

Calculation: Sound vs Light

From your bedroom window you see the lightening from a distant thunderstorm.

a. If it took the light 0.01s to reach you, how far away is the thunderstorm?

b. How long does will it be before you hear the thunder

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Investigation: Finding the Speed of Sound

Currently we do not have equipment that measuressound.

Instead we must measure 2 other quantities. These are:

1. ______________________

2. ______________________

Once we have measured these we can substitute them in the following equation to calculate sound:

Speed=¿

This investigation will be done as a whole class.

METHOD:

1. Nominate 3 people walk to the far end of the playing field.a. Person 1 will measure the distance walked using a trundle wheel. b. Person 2 will be responsible for lowering the trundle wheel (visual

signal)c. Person 3 will be responsible for creating the sound (audio signal)

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

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

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

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

6. Repeat investigation7. Find the mean of your results for time8. Use this value to calculate the speed of sound

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Health and Safety Check!

Make loud noise away fromears to protect ear drum

RESULTS:

The distance travelled by the sound was _________________ meters.

My ResultsTime (s) Average Time

(s)1 2 3

Explain below how you calculated the average time:

…………………………………………………………………………………………………

…………………………………………………………………………………………………

CLASS RESULTSStudent Number Average Time (s)

1234

5

6789

10

111213

14

15161718

Class Average Time:Investigation: Findings and Conclusions

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Use your investigation results to answer the following questions:

1. Use your calculate class average time to calculate the speed of sound.

…………………………………

2. What is the correct value for the speed of sound?

…………………………………………………………………………………………

3. How close were out results to the actual value? Why do they differ?

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

4. Why was it important for us to take multiple results and calculate an average?

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

5. Human reaction time is 0.7s. How could this impact our results? [e.g. would they be larger or smaller than expected?]

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

6. Can you suggest any changes to the experiment that would help to make you results more precise?1. ……………………………………………………………………………………………………………………………………………………………………………………

2. ……………………………………………………………………………………………………………………………………………………………………………………

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Can you solve this harder Echo question?

It will require you to do more than one distance calculation.

STRETCH

Lesson 5: Using Oscilloscopes

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Can you solve this harder Echo question?

It will require you to do more than one distance calculation.

Answer:

STRETCH

DEVELOPING Set up an oscilloscope to show a sound wave in transverse form

SECURE Explain the effect of changing the amplitude has on the sound wave shown on the oscilloscope.

EXTENDING Explain the effect that changing the frequency has on the sound wave shown on the oscilloscope.

SCIENTIFIC SKILLS Interpret the display on an oscilloscope.

Do Now: Knowledge and Revision Quiz

1. Using your prior knowledge from the Light topic can you label the following onto the transverse wave below: [4] Peak Trough Amplitude Highlight one complete wave

2. Sketch the particle diagram for a liquid. [2]

3. Describe the motion of the particles in a gas. [2]

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

4. Draw the circuit symbol for a resistor. [1]

5. What is the equation linking current, voltage and resistance? [1]

Score [ /10]

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Science Skill: Reading an Oscilloscope

Online Oscilloscope: https://academo.org/demos/virtual-oscilloscope/

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

Mark on the diagram above:

i. Time base (seconds/div)ii. Voltage/div iii.

Worked Example:

For the wave below:

a. Highlight one complete waveb. Label the time period of the wave c. Label the amplitude of the wave d. Using the seconds/div calculate the time base and frequency of the wavee. Using the volts/div calculate the amplitude of the wave

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Worksheet: Reading an Oscilloscope

Online Oscilloscope: https://academo.org/demos/virtual-oscilloscope/

For the waves below:

a. Highlight one complete waveb. Label the time period of the wave c. Label the amplitude of the wave d. Using the seconds/div calculate the time base and frequency of the wavee. Using the volts/div calculate the amplitude of the wave

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Practical: Reading an Oscilloscope

Once you have set up your Oscilloscope complete the following tasks.

Task 1: Volume

Start with a sound wave on your oscilloscope.

a. What is the Amplitude of the Sound wave? _________ V

Without changing the frequency, increase the volume of the sound wave.

b. What is the Amplitude of the Sound wave now? _________ V

Without changing the frequency, decrease the volume of the sound wave.

c. What is the Amplitude of the Sound wave now? _________ V

d. Using the axis below sketch out the different sound waves you saw. Remember to label the axis. You may wish to use different colours or add labels to show which sound wave was the loudest/quietest.

e. Which feature of the wave on the oscilloscope stayed the same in all 3 cases?

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

f. In one sentence, explain the link between Amplitude and Volume.

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

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

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Task 2: Frequency (Pitch)

Start with a sound wave on your oscilloscope.

a. What is the Time Period of the Sound wave? _________ s

Without changing the volume, increase the frequency of the sound wave.

b. What is the Time Period of the Sound wave now? _________ s

Without changing the volume, decrease the frequency of the sound wave.

c. What is the Time Period of the Sound wave now? _________ s

d. Using the axis below sketch out the different sound waves you saw. Remember to label the axis. You may wish to use different colours or add labels to show which sound wave was the loudest/quietest.

e. What feature of the wave on the oscilloscope stayed the same in all 3 cases?

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

f. In one sentence, explain the link between Frequency (Pitch) and Time Period.

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

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

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Adjust the signal generator to produce several different sounds. For each sound complete the results table below.

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]

STRETCH

Sound: Past Paper Questions

Q1.         

(a)     Claire is sitting in her bedroom listening to music. The sound she hears is

produced by the loudspeaker in her radio.

(i)      What is the loudspeaker doing to produce the sound?

         Tick the correct box.

blowing               

filtering                

spinning              

vibrating               1 mark

(ii)     How does the sound get from the radio to Claire?

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

.............................................................................................................1 mark

(iii)     What part of Claire’s ear detects the sound?

.............................................................................................................1 mark

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(b)     Lorna is in the school hall. The fire alarm rings and Lorna walks away from it.

(i)      When Lorna is further away, how loud does the alarm sound to her?

         Tick the correct box.

It sounds louder than before.                        

It sounds quieter than before.                       

It sounds the same as before.                       1 mark

(ii)     When Lorna is further away, how does the pitch of the alarm sound to her?

         Tick the correct box.

It has a higher pitch than before.                  

It has a lower pitch than before.                    

It has the same pitch as before.                    1 mark

Maximum 5 marks

 

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Q2.          A rocket was fired above a seaside town to call out the lifeboat crew.The rocket exploded, giving out light and sound at the same time.

(a)     Lisa was outside the town. She saw the flash of the rocket exploding and heard the bang.

(i)      Which sentence is true?Tick the correct box.

She heard the bang first.                                                      

She saw the flash first.                                                         

She heard the bang and saw the flash at the same time.    1 mark

(ii)     Give the reason for your answer.

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

............................................................................................................1 mark

(b)     Some people were nearer to the rocket than Lisa. How did the sound seem to them?

          Tick the correct box.

It was quieter.                        

It was louder.                         

It was higher pitched.            

It was lower pitched.              1 mark

Maximum 3 marks

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Q3.          An actor is on a stage in a theatre. A spotlight is shining on him.

(a)     A ray of light travels from the spotlight to the actor.

(i)      Which line shows the ray?  Give the correct letter.

…………1 mark

(ii)     How long does the light take to travel from the spotlight to the actor?

         Tick the correct box.

about a hundred millionth of a second          

about a tenth of a second                             

about a second                                             

about ten seconds                                         1 mark

(b)     The actor’s voice sounds different to the people in the front and back rows of the audience.

(i)      How does the actor’s voice sound different to a person in the back row?

……………………………………….……………………………………….

……………………………………….……………………………………….

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1 mark

(ii)     Complete the sentence with longer, shorter or exactly the same.

         When the actor is at the back of the stage, the time his voice

         takes to reach the audience is .…………………………… .1 mark

Maximum 4 marks

Q4.          (a)     The diagrams below show the patterns produced on an oscilloscope by threedifferent sound waves.

(i)      Which two waves have the same loudness?Write the letters.

............ and ............

         How do the diagrams show this?

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

..............................................................................................................2 mark

(ii)     Which two waves have the same pitch?Write the letters.

............ and ............

         How do the diagrams show this?

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

..............................................................................................................2 mark

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(iii)     Shuli is listening to a sound that produces the pattern below.

                       

         Describe how the sound that Shuli hears changes between X and Y.

.................................................................................................1 mark

(b)     The table below shows the maximum time a person can listen to music atdifferent sound levels without damage to the ear.

 

sound level (decibels) maximum time (hours)

86 8

88 4

90 2

92 1

94 0.5

          Estimate the maximum time a person could listen to a sound of 87 decibels.

............ hours1 mark

(c)     The diagram below shows part of the human ear.

          What happens to the ear drum as a sound gets louder?

.......................................................................................................................1 mark

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Maximum 7 marks

Q5.          John investigated which material would be best for soundproofing.He put a bell inside a box.He covered the bell with each material in turn.He put a sound sensor outside the box to record the sound level.

          He tested different materials and got the following results. 

material sound level (decibels)

no material added 65

A 40

B 58

C 50

D 35

(a)     On the chart below, draw the bar for material A.

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1 mark

(b)     How many types of material did John test?

          .............1 mark

(c)     Which material was best at stopping the sound going through?Give the correct letter.

          .............1 mark

(d)     Which two things should John have done to make his test fair?Tick the two correct boxes.

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2 marksMaximum 5 marks

 

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Q6.          Three pupils watched a firework display.

(a)     A man lit the fireworks. He wore ear defenders.

          Why should he wear ear defenders when he is close to loud fireworks?

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

......................................................................................................................1 mark

(b)     A rocket exploded making a loud sound and a bright flash.Peter, Sabrina and Jan were standing at different distances from the rocket.

          When the rocket exploded, Jan heard the quietest sound.Why did Jan hear the quietest sound?

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

.......................................................................................................................1 mark

(c)     Jan saw the flash before she heard the sound.

          What does this tell you about the speed of light and the speed of sound?

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

.......................................................................................................................1 mark

Maximum 3 marks

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Q7.          (a) (i)      Air contains nitrogen.In the box below draw five circles, , to show the arrangement of particlesin nitrogen gas.

          1 mark

(ii)     Zeena carries a personal emergency alarm.It uses nitrogen gas to produce a very loud sound.

(b)     Zeena pushes the lid down and nitrogen gas escapes through the diaphragm.The diaphragm vibrates and produces a sound.

          The pattern on the oscilloscope screen below represents the soundwaveproduced by the alarm.

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(i)      The loudness of the sound produced by the alarm decreases between X and Y.

         How can you tell this from the graph?

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

.............................................................................................................1 mark

(ii)     The pitch of the sound produced by the alarm stays the same between X and Y.

         How can you tell this from the graph?

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

.............................................................................................................1 mark

Maximum 5 marks

 

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