HIGHFIELDSSCHOOL

Physics Department

OCR GCSE Physics

P1 – Energy for the HomeStudent Support Booklet

Equations

Take the value of g to be 10 m/s2 or 10 N/kg unless stated otherwise in the question.

P1 – Key Words

Temperature A measure of how hot or cold something isThermograms A picture where colour is used to show different

temperaturesLatent heat The energy needed to change state (eg. Solid to liquid)

without changing the temperatureSpecific heat capacity

The energy needed to change the temperature of an object

Insulation Trapping air to reduce the transfer (movement) of energyExample: Fibreglass wool is a good insulator and is used in lofts

Conduction Energy is passed along from particle to particleExample: A metal spoon in a cup of tea will get hot as the metal is a good conductor of heat

Radiation The transfer of thermal (heat) energy to the surroundingsDouble Glazing A window with space between 2 pieces of glass.

The space is usually filled with gas.Sankey diagram Shows energy transformations (changes)Transverse wave Travels at right angles to the wave vibration:

Amplitude of a wave Each arrow shows the wave amplitude

Wavelength of a wave

The arrow shows the wavelength (the distance of one complete wave)

Frequency of a wave The number of waves passing in one secondElectromagnetic spectrum

Made up of seven types of waves

Diffraction Waves pass through an opening and spread outLaser Produces a narrow intense beam of lightMorse code Dots and dashes that represent the letters of the alphabet.

Used to send messages.

Total internal reflection

Light stays inside a material because it is reflected by the boundary between the material and air

Microwave Used for cooking and communicationDigital Signal Can only be on or off

Analogue Signal Can have any value – it is variableSeismometer Used to detect earthquakesEpicentre Earthquakes happen underground.

The epicentre is on the surface of the earth - above the focus point of the earthquake.

L Wave A type of earthquake wave.A surface wave – it travels out from the epicentre slowly

P Wave A type of wave created by an earthquakeA longitudinal waveTravels faster than an S Wave

S Wave A type of wave created by an earthquakeA transverse waveTravels slower than a P Wave

Seismic Wave A type of wave created by an earthquake (can be a p wave or an s wave)

Stratosphere Part of the atmosphereContains a gas called ozone.

Ozone Layer The layer of the atmosphere that protects us from Ultraviolet rays (these can cause skin cancer)

Melanin The pigment that causes skin to tanBoiling Point Temperature at which a liquid changes to a gasConvection Current When particles in a liquid or gas gain thermal energy from

a warmer region and move into a cooler region, taking energy with them.

Efficiency Ratio of useful energy output to total energy input; can be expressed as a percentage.

Infrared Waves Non-ionising waves that produce heat – used in toasters and electric fires.

Insulator A material that transfers thermal energy only very slowlyJoule A unit of energyEnergy The ability to do workMelting point Temperature at which a solid changes into a liquidPayback time The time it takes for the original cost outlay to be

recovered in savings

Module P1: Energy for the HomeP1a: Heating HousesWhen a body is heated, it gets hotter. A common misconception is that heat and temperature are the same thing. This item develops ideas to show that heat and temperature are different and that heat gain or loss does not always result in a temperature rise but can bring about a change of state. Because of a high specific heat capacity water needs lots of energy to increase its temperature. Because of this it also stores lots of energy and so is useful for transporting and transferring energy around homes.

GRADE G - D GRADE C GRADE B – A* Targets for Improvement

Understand that for warm bodies the rate of cooling depends on the temperature difference compared to the surroundings.

Understand that temperature is represented by colour in a thermogram.

Recognise, and understand the consequences of, the direction of energy flow between bodies of different temperatures.

Interpret data on rate of cooling.Explain how temperatures can be represented by a range of colours in a thermogram:

• hottest parts: white/yellow/red• coldest parts: black/dark blue/purple.

Describe temperature as a measurement of hotness on an arbitrary or chosen scale.

Understand that temperature is a measurement of the average kinetic energy of particles.

Recall that heat is a measurement of energy and ismeasured in Joules (J).

Describe how the energy needed to change the temperature of a body depends on:• mass• the material from which it is made• the temperature change.

Understand qualitatively and quantitatively the concept of the specific heat capacity of a material.

Use the equation:

energy = mass × specific heat capacity × temperature change

Describe heat as a measurement of energy on an absolute scale.

Use the equation, including a change of subject:

energy = mass × specific heatcapacity × temperature change

An initial calculation of temperature change may be

Describe an experiment to measure the energy required to change the temperature of a body.

required.

Interpret data which shows that there is no temperature change when materials are:• boiling• melting or freezing.

Understand qualitatively and quantitatively the concept of the specific latent heat of a material.Use the equation:

energy = mass × specific latent heat

Describe how, even though energy is still being transferred, there is no temperature change when materials are:• boiling• melting or freezing.

Use the equation, including a change of subject:

energy = mass × specific latent heat

Explain why the temperature does not change during a change of state.

P1a Activities1. Below is a thermogram. Explain what a thermogram is used for.

2. What is the difference between heat and temperature? Complete the table below to show their difference:

Heat Temperature

3. What is meant by the term specific heat capacity (SHC)?

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4. Match up each variable to the correct units.

5. Use the table of data to complete the calculations below:

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energy J/kg/°C

Joules, Jmass

°CSHC

temperature kilograms, kg

Material Water Oil Aluminium Iron Copper Lead Concrete

Specific Heat Capacity (J/kg/C)

4200 2100 900 490 390 130 850

a) How much energy is required to raise the temperature of 4.0 kg of Aluminium by 30 °C?

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b) How much energy is required to raise the temperature of 0.5 kg of water from 25 °C to boiling point?

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c) What is the temperature rise when an energy of 510 kJ is transferred to a 20 kg concrete block at 10 °C?

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6. Look at the graph below. Explain why the temperature does not change at 0 °C and 100 °C? Use ideas of particles and energy in your answer.

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Module P1: Energy for the HomeP1b: Keeping Homes WarmThe term insulation is used in the wider context of energy saving techniques in the home. This item develops ideas about the mechanisms of energy transfer by conduction, convection and radiation and the role they play in heat loss from homes. A poorly insulated home means that heat is being lost to the outside environment and more energy is needed to keep the home warm. Not only are energy resources being wasted but the homeowner is also paying for energy that is lost to the outside environment . This item develops ideas about using energy efficiently and reducing energy losses from homes.

GRADE G - D GRADE C GRADE B – A* Targets for Improvement

Explain why trapped air in a material is a very good insulator.

Recall that infrared radiation is:• reflected from a shiny surface• absorbed by a dull or rough surface.

Understand how absorption and reflection of infrared radiation can be applied in everyday situations.

Explain how energy is transferred in terms of:• conduction• convection• radiationand how such losses can be reduced in homes by energy saving measures to include:• loft insulation• double glazing• cavity wall insulation.

Understand and use the terms source and sink in the context of energy lost from houses.

Describe how energy is transferred by:• conduction - transfer of KE between particles, to include the role played by free electrons• convection – how expansion when a liquid or gas is heated causes a change of density whichresults in (bulk) fluid flow• radiation – infrared radiation is an electromagnetic wave and needs no medium.

Explain how there will be energy loss in a cavity wall and what further measures could be taken to limit this loss.

Describe everyday examples of energy saving methods in the home.

Explain how the property that air is a very good insulator is used to keep homes warm:

• fibreglass, mineral or rock wool in loft insulation• double glazing in windows• insulation foam or fibreglass in cavity walls• curtains at windows.

Describe other energy saving measures:• reflective foil in or on walls• draught-proofing.

Use the equation:

given the useful energy output and the total energy input; efficiency can be expressed in ratio or percentage terms.

Interpret data for different energy saving strategies to include calculations involving:• initial cost• annual saving on energy bills• payback time.

Use the equation:

given the wasted energy and total energy input; efficiency can be expressed in ratio or percentage terms.

Interpret and complete information presented in Sankey diagrams, to show understanding that energy is conserved.

Explain, in the context of the home, the concepts of conduction, convection and radiation (absorption andemission) in terms of:• the design features of the home• the design and use of everyday appliances in the home• energy saving strategies.

Use the equation:

to calculate the useful energy output, total energy input or wasted energy, which may be used to complete a Sankey diagram.

Efficiency can be expressed in ratio or percentage terms.

P1b Activities1. Using the diagram below explain what is meant by conduction, convection and radiation:

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2. Heat can be transferred from a house as shown below. Annotate the diagram to explain how energy losses can be reduced.

3. Complete the following table on payback time:

Insulation Cost to install £ Saving per year £

Payback time

Cavity wall 500 50

Double Glazing 3000 50

Loft 250 2 years

Draught Proofing

20 4 years

4. Complete the following calculations:

a) How efficient is a cyclist who uses 200 J of energy to produce 30 J of useful energy?

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b) A motor has an efficiency of 40%. How much useful energy is produced from 250 J?

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5. A light bulb is supplied with 100 J of energy and transfers 20 J to useful energy. Draw a labelled Sankey diagram below:

Module P1: Energy for the HomeP1c: A spectrum of wavesInfrared radiation has been introduced in the context of heat transfer, but before further uses of electromagnetic (em) waves are considered, the properties of transverse waves are introduced. The electromagnetic spectrum is outlined, with a focus on the communication uses of non-ionising em waves. Some of the practical limitations of using waves are related to wavelength.

GRADE G - D GRADE C GRADE B – A* Targets for Improvement

Identify and name the main features of a transverse wave:• trough and crest• amplitude• wavelength.

Describe the main features of a transverse wave:• trough and crest• amplitude• wavelength• frequency – as the number of complete waves, cycles, or oscillations per second.

Recall that all electromagnetic waves travel at the same high speed in space or a vacuum.

Use the equation:wave speed = frequency × wavelength

Determine the value of the wavelength or the frequency of a wave from a diagram and be able to use the value in the equation:

wave speed = frequency × wavelength

Use the equation including a change of subject and/ or use of standard form (or the use of a scientific notation calculator):

wave speed = frequency × wavelength

Recall that electromagnetic waves travel in straight lines through a particular medium.

Use basic ray diagrams to demonstrate reflection at multiple plane (flat) boundaries.

Describe a diffraction pattern for waves, including the significance of the size of the opening or barrier relative to the

Use ray diagrams to describe reflection at single plane (flat) boundaries.

Recognise that refraction involves a change in direction of a wave due to the wave passing from onemedium into another.

Understand why refraction occurs at the boundary between mediums.

Describe diffraction of waves at an opening.

wavelength.

Identify the seven types of electromagnetic waves that comprise the spectrum and place them in ascending order of frequency.

Describe an example of a communications use forradio, microwave, infrared and visible light.

Identify the seven types of electromagnetic waves that comprise the spectrum and place them in order of frequency or wavelength.

Relate the size of a communications receiver to thewavelength for radio, microwave, infrared and visible light.

Describe and explain the limiting effects of diffraction on wave based sensors, to include:• telescopes• optical microscopes.

P1c Activities1. Label the amplitude, wavelength, trough and crest of the wave below:

2. If the above wave occurred in one second then what is the frequency of the wave?

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3. Complete the following calculations:

a) A wave has a frequency of 20 Hz and a wavelength of 20 m. What is the speed of the wave?

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b) A wave travels at 150 m/s and has a wavelength of 30 m. What is the frequency of the wave?

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c) If 12 waves pass a point every second and they are travelling at 60 m/s, what is the distance from the crest of one wave to the crest of the next wave?

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4. Draw a labelled diagram below to show what happens when a single ray of light hits a mirror at an angle of 45°.

5. Use the diagram below to explain what happens when light travels from air into glass. Use ideas about particles, density and wave speed in your answer.

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6. Write the seven electromagnetic waves in order from low frequency to high frequency:

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7. Under what conditions do you get maximum diffraction?

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Module P1: Energy for the HomeP1d: Light and LasersThe use of light as a source of digital communication, from Morse signalling to present day laser technology, has made rapid communication possible. This item develops ideas about communication at the speed of light, including applications of Total Internal Reflection.

GRADE G - D GRADE C GRADE B – A* Targets for Improvement

Describe how, historically, the use of light greatly increased the speed of communication but that it requires the use of a code.

Describe how light was used as a means of communication:• signals sent in the form of Morse code which is a series of on off signals• signals relayed between stations to cover larger distances.

Describe why Morse code is a digital signal.

Explain the advantages and disadvantages of using light, radio and electrical signals for communication.

Recognise, in the context of optical fibres, where Total Internal Reflection (TIR) happens:

• glass-air boundary

• water-air boundary

• perspex-air boundary.

Describe what happens to light incident on a boundary, e.g. glass-air, water-air or perspex-airboundary, below, at and above the critical angle.

Understand how transfer of light along an optical fibre depends on the critical angle of the incident light.

Describe applications of Total Internal Reflection (TIR) in fibre optics.

Understand how light and infrared radiation can travel along an optical fibre from one end to another by reflection from the sides of the fibre.

Understand how the properties of light produced by lasers allows them to be used for:• surgery and dental treatment• cutting materials in industry• weapon guidance• laser light shows.

Recall that a laser produces a narrow beam of light of a single colour (monochromatic).

Explain why most lasers produce an intense coherent beam of light:• waves have the same frequency• waves are in phase with each other• waves have low divergence.

Explain how a laser beam is used in a CD player by reflection from the shiny surface:• information is stored on the bottom surface• information is stored digitally• information in the form of patterns of bumps (known as pits)• a CD will contain billions of pits.

P1d Activities1. Label each of the diagrams below as reflection or refraction:

2. Draw a ray of light as it undergoes Total Internal Reflection (TIR) through the optical fibre below:

3. Give three uses of Total Internal Reflection (TIR):

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4. Why is Morse code considered to be a digital signal?

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5. Lasers produce a narrow intense beam of light which is

monochromatic. What does monochromatic mean?

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6. Give three uses of lasers:

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7. Explain why most lasers produce an intense coherent beam of light. Decide if the following statements are true or false:

Statement True

False

Waves have different frequenciesWaves are in phase with each otherWaves have low divergence

8. Explain how a laser beam is used in a CD player by reflection from the shiny surface:

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9. Use the information in the table to work out which way the light ray will bend (towards/away from the normal)?

a) from air to

diamond………………………………………..

b) from water to

glass…………………………………………

c) from diamond to water

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Substance Density in kg/m³

Water 1000

Glass 2400-2800

Diamond 3500

Module P1: Energy for the HomeP1e: Cooking and communicating using wavesAll radiations in the electromagnetic spectrum can be dangerous but they also have many uses. Infrared radiation and microwaves are useful for cooking since they cause heating in objects that absorb them. Microwaves are used for mobile phone communications. This item develops ideas about the properties of infrared and microwave radiation and examines their dangers and uses.

GRADE G - D GRADE C GRADE B – A* Targets for Improvement

Interpret information on the electromagnetic spectrum to include microwaves and infrared radiation.

Understand how the emission and absorption of infrared radiation is affected by the properties of the surface of an object. Properties to include:

• surface temperature• colour (black or white)• texture (shiny or dull).

Recognise that microwaves cause heating when absorbed by water or fat and that this is the basis of microwave cooking.

Describe properties of infrared radiation:

• heats the surface of the food• is reflected by shiny surfaces.

Describe properties of microwaves:

• penetrate (about 1cm) into food• are reflected by shiny metal surfaces• can cause burns when absorbed by body tissue• pass through glass and plastics.

Explain how microwaves and infrared transfer energy to materials:

• infrared is absorbed only by particles on the surface of the food increasing their KE• KE is transferred to the centre of the food by conduction or convection• microwaves are absorbed only by water or fat particles in outer layers of the food increasing their KE.

Describe how the energy associated with microwaves and infrared depend on their frequency and relate this to their potential dangers.

Recall that mobile phones use microwave signals.

Describe factors that limit the transmission of information over large distances using microwaves.

Explain how signal loss with microwaves happens because of:• adverse weather and large areas of surface water scatter signals

• loss of line of sight due to curvature of the Earth• no diffraction of microwaves around large objects• interference between signals.

Describe how the problems of signal loss are reduced by:• limiting the distance between transmitters• high positioning of transmitters.

Describe some concerns about children using mobile phones.

Recall that different studies into the effects of mobile phone use have reached conflicting conclusions.

Describe why there may or may not be dangers:

• to residents near the site of a mobile phone transmitter mast• to users of mobile phones.

Describe how potential dangers may be increased by frequent use.

Explain how publishing scientific studies into the effects of mobile phone microwave radiation enables results to be checked.

Understand that in the presence of conflicting evidence individuals and society must make choices about mobile phone usage and location of masts in terms of balancing risk and benefit.

P1e Activities1. Write the corresponding label for each letter. One has been done for you.

A = ……………………………. B = …………………………… C = ……………………………

D = ……………………………. E = ..….Ultraviolet (UV)..…. F = ……………………………

G = …………………………….

2. Add an arrow above the wave to show in which direction the frequency increases. Label it “increasing frequency”.

3. For each of the statements below you need to say whether they describe properties of infra-red radiation, microwaves or both. Tick the correct box.

INFRA-RED RADIATION

MICROWAVES

Penetrate 1 cm into food.

Reflected by shiny surfaces.

Can cause burns when absorbed by body tissue.

Heats the surface of the food.

Pass through glass and plastics.

Cause heating when absorbed by water or fat.

KE of particles is transferred into the centre of food by conduction or convection.

B C D E F GA

4. Which of the electromagnetic waves are used for mobile phone communication?

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5. What factors affect signal loss of microwaves?

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6. For one of the factors you have given for Question 5, explain how the problem of signal loss can be reduced.

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7. Complete the table below on the risks and benefits of young people using mobile phones:

Risks of young people using mobile phones.

Benefits of young people using mobile phones.

8. There is a lot of conflicting evidence about the dangers of using mobile phones. Why is it important for scientists to work collaboratively and use peer review when carrying out research into such an area?

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Module P1: Energy for the HomeP1f: Data TransmissionInfrared radiation is not only useful for cooking and heating. It is used in remote controls to make life easier, whether it is changing channels on the television, opening car doors or opening the garage door when we get home on a cold, wet evening. Infrared radiation is also used to carry information in signals that can be transmitted over long distances using optical fibres. This item considers how we use infrared radiation.

GRADE G - D GRADE C GRADE B – A* Targets for Improvement

Describe everyday uses of infrared radiation to include:• in remote controls (TV, video and DVD players, automatic doors)• short distance data links for computers or mobile phones.

Describe how infrared signals can carry information to control electrical or electronic devices.

Explain how the signal from an infrared remote control uses a set of digital signals (or codes) tocontrol different functions of electrical or electronic devices.

Understand how passive infrared sensors and thermal imaging cameras work:• infrared sensors detect body heat.

Describe the differences between analogue and digital signals:• analogue signals have a continuously variable value• digital signals are either on (1)

Understand why it is easier to remove noise from digital signals.

Explain how the properties of digital signals played a part in the switch to digital TV and radio broadcasts, to include use of multiplexing.

or off (0).Describe the transmission of light in optical fibres:• optical fibres allow the rapid transmission of data• optical fibres allow the transmission of data pulses using light.

Describe advantages of using optical fibres to allow more information to be transmitted:• multiplexing• lack of interference in the final signal.

P1f Activities1. Use words in the box to complete the following cloze passage:

Infra-red radiation has a ……………….. frequency than visible light and a

……………….. wavelength than microwaves. Infra-red radiation is used in

cooking but can also be used for ………………… .One everyday use of

infra-red radiation is in ……………….. controls (e.g. for TV and DVD

players) where ……………….. signals are used to control different

functions on ……………….. devices. Infra-red sensors and ………………..

imaging cameras work by detecting the ……………….. energy transferred

from the body.

2. Draw a diagram to represent an analogue and digital signal in the

boxes below:

3. What is the main difference between an analogue and a digital signal?

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higher lower remote analogue longer analogue digital

shorter communication kinetic thermal heat electrical

Analogue Digital

4. Give one use for both an analogue and a digital signal:

Analogue: ……………………………………………………………………………………………

Digital: …………………………………………………………………………………………………

5. List three advantages of transmitting information using digital signals rather than analogue signals.

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6. What is multiplexing? Use ideas about digital signals, combined signals and a demultiplexer in your answer.

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7. Explain, with the help of a diagram, why interference does not degrade a digital signal but can affect an analogue signal.

8. What are the advantages of using optical fibres to transfer digital signals?

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Module P1: Energy for the HomeP1g: Wireless SignalsToday’s hi-tech world demands that people can always receive both phone calls and email very rapidly. This item develops ideas about global communication, the benefits of wireless transmission, and the impact of this culture on modern society. The expanding use of digital signals is examined.

GRADE G - D GRADE C GRADE B – A* Targets for Improvement

Describe how radiation used for communication can be reflected.

Recognise that wireless technology uses electromagnetic radiation for communication.

Describe the advantages of wireless technology:• no external/direct connection to a telephone line needed• portable and convenient• allows access when on the move but an aerial is needed to pick up the signals.

Recall how radiation used for communication can be refracted and reflected and how this can be an advantage or disadvantage for good signal reception.

Describe common uses of wireless technology:• TV and radio• mobile phones• laptop computers.

Explain how long-distance communication depends on:• the refraction and resulting reflection of waves from the ionosphere• being received by and re-transmitted from satellites.

Recall that the refraction and reflection in the ionosphere is similar to TIR for light.

Interpret data, including information given in diagramform, on digital and analogue signals.

Understand why nearby radio stations use different transmission frequencies.

Describe advantages and disadvantages of DAB

Explain how the refraction and diffraction of radiation can affect communications:• refraction at the interfaces of different layers of Earth’s atmosphere

broadcasts:• more stations available• less interference with other broadcasts• may give poorer audio quality compared to FM• not all areas covered.

• diffraction by transmission dishes results in signal loss.

Explain the advantage of digital radio, in terms of lack of interference, including that between other broadcasts/stations.

P1g Activities1. What are the advantages of using wireless technology?

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2. Wireless signals can be reflected off buildings and other large objects such as hills (see below). This can lead to ghosting. What is ghosting and why does it happen?

3. Wireless signals are also reflected off the atmosphere. What is the name of this layer of the atmosphere called?

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4. Why do nearby radio stations need to use different transmission frequencies?

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5. What are the advantages and disadvantages of using DAB instead of FM?

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5. Wireless signals can also be transmitted using refraction as shown in the diagram below. Explain what type of electromagnetic wave is shown by A and C.

6. Why might a house at the bottom of a hill be able to receive a good radio signal but get very poor TV reception?

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7. Explain how long-distance communication depends on:

a) the refraction and resulting reflection of waves from the ionosphere

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b) being received by and re-transmitted from satellites.

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A: …………………………………………………..

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C: …………………………………………………..

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Module P1: Energy for the HomeP1h: Stable EarthWaves carry information. The information can be extracted even from naturally occurring waves, such as seismic waves generated within the Earth. Some waves are potentially harmful to living organisms. Incidents of skin cancer are rising, even in the UK. This item develops ideas surrounding these and other observations. It also examines how climate is being affected by natural and human activity.

GRADE G - D GRADE C GRADE B – A* Targets for Improvement

Describe earthquakes as producing shock waves which can:• be detected by seismometers• be recorded on a seismograph• cause damage to buildings and the Earth’s surface• cause a tsunami.

Recall that two types of seismic waves are:• longitudinal P waves which travel through both solids and liquids and travel faster than S waves• transverse S waves which travel through solids but not through liquids and travel slower than Pwaves.

Describe how data on seismic waves transmitted through the Earth can be used to provide evidence for its structure:• P waves travel through solid and liquid rock (i.e. all layers of the Earth)• S waves cannot travel through liquid rock (i.e. the outer core).

Recall that exposure to ultraviolet radiation can cause:• suntan• sunburn• skin cancer• cataracts• premature skin aging.

Recognise that sunscreens (e.g.

Explain how darker skins reduce cancer risk:• absorb more ultraviolet radiation• less ultraviolet radiation reaches underlying body tissues.

Interpret data about sun protection factor (no recall is

Explain how the ozone layer protects the Earth from ultraviolet radiation.

Describe how:• environmental pollution from CFCs has depleted the ozone layer• this allows more ultraviolet

sun block or sun cream) can reduce damage caused by ultraviolet radiation:• less damage when higher factors are used• high factors allow longer exposure without burning.

expected).

Calculate how long a person can spend in the Sun without burning from knowledge of the sun protection factor (SPF) of sunscreens (e.g. sun block or suncream).

Describe how people have been informed of the risk of exposure to ultraviolet radiation, including from the use of sun beds, in order to improve public health.

radiation to reach Earth• the potential danger to human health increases because of this.

Recall that the discovery of the reduction of ozone levels over Antarctica was unexpected.

Describe how scientists used existing scientific ideas to explain their measurements.

Describe how scientists verified their measurements of ozone reduction, and the steps they took to increase confidence in their explanation:• measurements repeated with new equipment• measurements repeated by different scientists• predictions tested based on the explanation.

Describe how the discovery of the hole in the ozone layer over Antarctica changed the behaviour of society at an international level.

P1h Activities1. Match the correct word with its definition:

2. What are the differences between P waves and S waves? Complete the table below:

P waves S waves

3. “The Earth has a liquid outer core”. Use the diagram below to explain the evidence for this statement.

4. Name three effects of long term exposure to ultraviolet radiation.

seismometer

seismograph

tsunami

transverse

longitudinal

Records shock waves produced by earthquakes.

A type of wave where the particles vibrate parallel to the direction of wave movement.

The point below the Earth’s surface where the earthquake happens.

The point on the Earth’s surface above the focus.

Detects shock waves produced by earthquakes.

focus

epicentre

A type of wave where the particles vibrate perpendicular to the direction of wave

movement.Can be caused by the shock waves produced

by earthquakes.

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5. Explain how darker skins reduce cancer risk.

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6. In the upper part of the Stratosphere there is a layer called the Ozone layer. How does this layer protect the Earth from UV radiation? What caused the ozone layer to become depleted?

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7. The Sun index gives the maximum length of time you can safely remain in the Sun without sunscreen on. The Sun Protection Factor (SPF) can be found on sunscreen bottles.

Sun Index

Risk

1 - 2 low risk

3 - 4

avoid being in sun for more

than 1 - 2 hours

5 - 6burns in 30 - 60 minutes

7 - 10

severe burns in 20 - 30 minutes

How long could you spend in the Sun with a sunscreen with SPF of 10 when the Sun index is 5?

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How long could you spend in the Sun if the Sun index is 8 and the sunscreen has an SPF of 8?

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These are six mark questions.

You will also be assessed on the quality of your written communication

(spelling, punctuation and grammar).

The 6 mark question template (you can photocopy this page and use it to practice each of the questions)

6 marks? No problem! Just remember SSS

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Science – write down the key words/points you will use:

Structure – Write a brief plan of the order you will write your points :1.

2.

3.

4.

5.

6.

SPAG (spelling, punctuation and grammar).

Make sure you have used full stops, commas, and other

Now you are ready to write your answer!