Key stage 3 Physics Revision 3

Energy Resources, Energy Transfers, Light, Sound

Objective

I can:

Self

assessment

before

revision

Self

assessment

after

revision identify some common fuels identify fuels as sources of light, heat and movement, all of which can be called energy

name several fossil fuels and explain why they are described as fossil explain that fossil fuel reserves are limited because they are non-renewable provide coherent accounts of the formation or use of fossil fuels identify the main renewable energy resources explain the term 'renewable energy resource' describe the operation of a device driven by a renewable energy source know that living creatures need energy to live identify the energy contents of a sample of food, eg from a label produce and present records of temperature rise to compare energy output of different foods

draw a food chain and extend it to show the link to sunlight and to themselves describe how energy from the Sun links to everyday activities explain why using my senses is not a reliable way to measure temperature understand the need for a scale of temperature and use the Celsius scale of temperature

describe the flow of heat (energy) in an everyday situation of temperature change relate a flow of heat to change in temperature relate a difference in temperature to a flow of heat explain that whether things feel warm or cold to the touch will depend on their conductivity as well as their temperature

classify materials as conductors or insulators of heat describe evidence that gases and liquids are poor conductors of heat apply the particle model to explain why metals are good conductors and why fluids are poor conductors of heat

describe the expansion of all three states of matter on heating and contraction on cooling (in terms of particles speed)

relate different states to the different motion and arrangement of particles describe how air or water moves when part is heated or cooled distinguish between transfer of thermal energy via conduction and convection and transfer by radiation, with reference to requirement for a medium

describe and explain how a house can be fitted out to reduce heat loss use the terms 'melting point' and 'boiling point' and give some important examples describe what happens to the temperature of the substance as it melts/boils describe, with reasons, what would happen if the liquid/solid were cooled/heated again

use the particle model to associate heating and cooling with changes of state recognise that light is all around state that light travels much faster than sound describe evidence to support the idea that light travels in a straight line represent simply the path of light as rays use words precisely when describing the effects of materials explain that some light may be absorbed when it hits an object

explain how non-luminous objects are seen, using words and ray diagrams make predictions about the way that light is reflected from plane surfaces describe the nature of the image formed in a plane mirror, eg inverted suggest how such an image is formed explain everyday reflections using words and/or ray diagrams make generalisations from their observations of refraction draw selected angles of incidence and refraction and use these to establish generalisations,

draw a ray diagram to explain a phenomenon of refraction identify the colours of the spectrum describe how white light is dispersed by a prism to give a range of different colours describe how a spectrum can be recombined to form white light investigate how coloured filters change white light suggest how filters affect white light investigate how coloured light can be combined to produce new colours investigate how coloured objects appear in white light and in different colours of light

identify and explain patterns of my observations using appropriate vocabulary describe, using annotated diagrams and the correct scientific terminology, how the path of light can be altered by reflection or refraction

describe different sounds using appropriate terms, eg high, low and soft explain that sounds are made as a result of vibrations and identify the source of vibration in a range of cases

suggest ways to change the pitch and loudness of sounds from musical instruments

make generalisations about changing sounds in musical instruments make generalisations about changing sounds related to vibrations use the terms 'frequency' and 'amplitude' in describing sound waves relate high pitch to high frequency and high amplitude to loudness compare and interpret wave forms in terms of pitch and loudness state that sound cannot travel through a vacuum but can travel through solids, liquids and gases

describe how sounds travel through solids, liquids and gases explain in terms of the particle model why sound needs a medium explain how sound travels at different speeds in different types of material explain everyday phenomena in terms of the different speeds at which sound travels in air and solids

describe how hearing ability changes with age and that hearing can be damaged describe examples of animals detecting sounds that are inaudible to human ears identify the parts of the ear on a diagram or model describe how vibrations in the air are transmitted and translated into electrical signals, which pass to the brain

use a sound-level meter or other method of comparing sounds describe sensations of temporary deafness or tinnitus and indicate how these arise

Key words

Use your exercise book, text books and other revision material to give definitions for the following key

words and phrases related to Energy Resources, Energy Transfers, Light and Sound.

Absorb

Amplitude

Conduction

Conductor

Contraction

Convection

Expansion

Fossil Fuel

Frequency

Heat

Insulator

Luminous

Non-Luminous

Non-Renewable energy resources

Opaque

Radiation

Reflect

Refract

Renewable energy resources

Spectrum

Temperature

Transparent

Sample Exam Questions

The mark scheme for these questions, along with further practice questions, can be found at

http://mrblackstone.wikispaces.com/

Level 4

1. (a) Aisha drops a stone into a pond. She hears the sound and she watches ripples spreading out across the pond.

Sound, ripples on water, and light travel at different speeds.

(i) Which travels fastest: sound or ripples on water or light?

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

1 mark

(ii) Which travels most slowly: sound or ripples on water or light?

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

1 mark

(b) Which sentence about sound is correct? Tick the correct box.

Sound cannot travel through air.

Sound cannot travel through stone.

Sound cannot travel through a vacuum.

Sound cannot travel through water.

1 mark

Maximum 3 marks

2. The drawings below show six ways of providing energy.

coal fire

burns coal to provideheat

A

turbine

turns a generator toprovide electricity

B

petrol generator

burns petrol to provideelectricity

C

gas boiler

burns gas to provideheat

D

solar panel

uses solar energy toprovide heat

E

wave turbine

uses wave energy toprovide electricity

F

solar panel

(a) From the drawings, give the names of two fossil fuels.

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

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

2 marks

(b) (i) What is the source of energy for a solar panel?

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

1 mark

(ii) Why can the solar panel not work at night?

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1 mark

(c) What makes the blades of the turbine in drawing B go round?

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1 mark

(d) Renewable energy resources will not run out.

From the drawings, give one energy source that will not run out.

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1 mark

maximum 6 marks

Level 5

3. Satellites can sometimes be seen in the night sky. They look like stars slowly moving across the sky.

(a) We can see stars because they are light sources. They give out their own light. Satellites do not give out their own light. Explain why satellites can be seen in the clear night sky.

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2 marks

(b) Sometimes a satellite suddenly stops being visible. However, you can usually see it again in another part of the sky later the same night. This can happen when there are no clouds in the sky and the satellite is overhead.

Why does the satellite suddenly stop being visible?

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

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1 mark

(c) Give one use of satellites in orbit around the Earth.

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1 mark

Maximum 4 marks

4. The dotar is a musical instrument with two strings.

(a) Aftal plays the dotar very quietly.

What must he do to the strings to make a louder sound?

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

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1 mark

(b) Aftal makes the strings tighter so they vibrate more quickly.

How does this affect the sound produced by the strings? Tick the correct box.

The sound has a lower pitch.

The sound is louder.

The sound has a higher pitch.

The sound is quieter.

1 mark

(c) One of the strings is thicker than the other, so it vibrates more slowly.

In what way is the sound made by the thicker string different from the sound made by the thinner string?

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

1 mark

(d) Aftal played the dotar near a microphone connected to an oscilloscope. The diagrams below show the patterns made by four sounds.

A B

C D

(i) How does the sound shown in trace A differ from the sound in trace B?

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1 mark

(ii) How does the sound shown in trace A differ from the sound in trace C?

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

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1 mark

maximum 5 marks

Level 6

5. (a) Jacquie has a mobile phone. Energy is stored in the battery of the phone. The drawing shows the battery being charged.

(i) Which energy transfer takes place in the battery as it is being charged? Tick the correct box.

chemical to sound sound to thermal

electrical to chemical thermal to electrical

1 mark

(ii) When the battery is fully charged, Jacquie unplugs the phone.

Which energy transfers take place when the mobile phone rings? Tick the correct box.

chemical to electrical to sound

electrical to chemical to sound

kinetic to electrical to sound

thermal to electrical to sound

1 mark

(b) Jacquie can change the ring-tone of her phone. The diagrams below show the patterns made by four sound waves on an oscilloscope screen. They are all drawn to the same scale.

Write the letter of the sound wave that matches each of the descriptions below.

(i) a loud sound with a low pitch .................

(ii) a quiet sound with a high pitch .................

(iii) a loud sound with a high pitch .................

3 marks

Maximum 5 marks

6. Fossil fuels are used to generate electricity, but over half of the world’s population uses biomass as a fuel.

(a) What is ‘biomass’, which is used as a fuel?

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

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

1 mark

(b) Biomass and fossil fuels are both energy resources. What is the original source of this energy?

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

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

1 mark

(c) Give the names of three fossil fuels which are often burned to generate electricity.

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

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

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

1 mark

(d) Fossil fuels are often described as non-renewable energy resources. Explain why they are called ‘non-renewable’.

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

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1 mark

(e) There are advantages and disadvantages of burning different fuels.

(i) Give one advantage of using biomass rather than fossil fuel as an energy resource.

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

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1 mark

(ii) Give one advantage of using fossil fuel rather than biomass as an energy resource.

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1 mark

(iii) Give one disadvantage of using both fossil fuel and biomass.

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

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1 mark

Maximum 7 marks

Level 7

7. (a) Peter had two different coloured tennis balls as shown below.

He shone white light through a red filter onto each ball.

(i) experiment 1

The white ball appeared red. Explain why this ball appeared red.

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

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

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

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2 marks

(ii) experiment 2

What colour did this ball appear?

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

Explain your answer.

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

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2 marks

(b) Peter set up a different experiment. He cut three holes in a piece of card. Two of the holes were covered by coloured filters as shown below.

red filter

green filter

clear

Peter placed a red filter between the piece of card and a white screen. He shone white light at the piece of card with three holes in it.

whitelight

red filter

white screen

What would Peter see on the screen?

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

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1 mark

maximum 5 marks

8. Three pupils took part in an investigation into the speed of sound. All three pupils stood 1020 m from an explosion.

Sylvia wore a blindfold.

Paul wore ear defenders.

James wore a blindfold and ear defenders. He rested his head on a wooden stick pushed into the ground so that he could feel vibrations.

The explosion produced sound and light at the same time. The table shows the speed of sound in two different materials.

material Speed of sound

(m/s)

air 340

soil 3200

(a) Use all the information above to help you answer parts (i) and (ii) below.

(i) In which order would the pupils notice the explosion?

first ......................................................................................................

second ................................................................................................

third .....................................................................................................

1 mark

(ii) From the information given, calculate the time it would take for the sound to travel through the air to Sylvia.

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

.......................................................................................................... s

1 mark

(b) Another pupil, Nasah, stood 2000 m away from the explosion.

(i) The sound heard by Nasah was quieter than the sound heard by Sylvia. The further sound travels the quieter it becomes. Give the reason for this.

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

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1 mark

(ii) The oscilloscope trace below represents the sound Sylvia heard.

The sound Nasah heard was quieter but the pitch was the same.

On the right-hand grid, draw the trace to show the pattern of the sound Nasah heard.

2 marks

maximum 5 marks

Level 8

9. The diagram shows a boat using an echo sounder. It sends a pulse of sound waves which is reflected from the sea bottom. The reflected sound waves are detected by a sensitive microphone.

sea

sea bed

echo sounder

The time between sending and receiving the pulse is 0.005 s. The device calculates the depth of the sea, using the speed of sound in sea water, which is 1500 m/s.

(a) Calculate the depth of the sea. Show your working.

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2 marks

(b) The boat moves into very deep water. Explain why the reflected pulse is too weak to be detected.

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1 mark

(c) The boat’s ‘echo sounder’ could not be used in an aeroplane to measure its height above the ground unless it had been modified.

Explain why the device will not give correct heights above the ground.

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1 mark

Maximum 4 marks

10. In a hot-air balloon, propane is burned. This reaction is used to heat the air in the balloon.

(a) in each propane molecule, carbon and hydrogen atoms are held together by bonds as shown below.

C C C H

H H H

H H H

H

The equation for the burning of propane is:

C3H8 + 5O2 3CO2 + 4H2O

(i) Carbon-carbon and carbon-hydrogen bonds are broken during the reaction. State another chemical bond that is broken in this reaction.

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1 mark

(ii) What new chemical bonds are formed during the burning of propane?

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2 marks

(b) Energy is required to break chemical bonds, but energy is released when chemical bonds are formed.

In the reaction of propane and oxygen, the total energy required to break bonds is less than the total energy released by forming new bonds.

What is the evidence for this?

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

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1 mark

Maximum 4 marks