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Science Interactive LTD
Science Interactive LTD. PO BOX 50764 LONDON NW6 9AT email: [email protected] web: www:science-interactive.co.uk
Science Interactive LTD Copyright 2005
Science base multimedia CD-ROM for PC is a collection of 38 units or tools totalling over 1150PowerPoint slides . Each unit covers a wide range of different delivery and learning styles, offering anexciting way to involve your pupils during lessons or revision sessions. All styles of teaching and
learning are supported through use of high quality images , graphics , challenging exercises andquestions . Units can be used in the classroom via an interactive whiteboard , data projector or usedduring individual study via a PC or school network .
Unit 19: The Transitional Metals
Unit 18: Metals and their Properties
Unit 17: The Alkali MetalsUnit 16: The Periodic Table and its Elements
Unit 15: Genetic Engineering
Unit 14: Evolution and Human Impact
Unit 13: Inheritance and Selection
Unit 12: Mitosis and Meiosis
Unit 11: Flow of Energy and Elements through the Environment
Unit 10: Water Transport in Plants
Unit 9: Photosynthesis in Green Plants
Unit 8: Drugs and Bad Body Maintenance
Unit 7: Hormones and the Endocrine System
Unit 6: Human Homeostasis
Unit 5: Nervous System and the Senses
Unit 4: The Respiratory System
Unit 3: Healthy Body and Immunity
Unit 2: The Circulatory System
Unit 1: The Digestive System
Unit 38: Cells, Tissue, Organs and Organs systems
Unit 37: Natural Forces
Unit 36: Sound and HearingUnit 35: The Alkaline Earth Metals
Unit 34: The Earth and Plate Tectonics
Unit 33: Earth and Space
Unit 32: Newton's Forces and the Effects of Forces
Unit 31: Radioactivity
Unit 30: Light and the Electromagnetic Spectrum
Unit 29: Electricity
Unit 28: Generating Electricity and its Domestic Use
Unit 27: Energy
Unit 26: Rates of Reaction
Unit 25: The Noble Gases, their Properties and Uses
Unit 24: The Halogens, their Uses and Compounds
Unit 23: Ionic and Covalent Compounds
Unit 22: Elements, Molecules and Compounds
Unit 21: Rock Cycle
Unit 20: Crude Oil and its Products
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Science Interactive LTD Copyright 2005
Unit 27Energy
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Unit 27: EnergyUnit 27: Energy Science Interactive LTD Copyright 2005
Understand: Keywords:1. The different types of energy and that energy is
measured in joules.2. That energy cannot be destroyed or created,
only transformed from one type to another.3. How to calculate the energy efficiency of a
device.4. That heat energy can be transferred by
convection, conduction and radiation.5. Some of the major sources of energy including
fossil fuels.6. How we use energy around the home for
lighting, heating, cooking and leisure activities.
7. That reducing energy use can save money andreduce the need to combust fossil fuels like oiland natural gas.
8. That using renewable methods of generatingelectricity provides alternatives to meeting theenergy demands of a population.
Energy, Chemical, Gravitational, Potential,Elastic, Kinetic, Sound, Light, Heat,Electrical, Transformed, Transferred, Device,Joule, Kilojoules, Sources, Fossil, Fuels,Efficiency, Renewable, Solar, Power, Tidal &
Geothermal .
web: www.science-interactive.co.uk email: sales science-interactive.co.ukScience Interactive LTD PO BOX 50764 LONDON NW6 9AT
Click mouse to begin
S i I i LTD C i h 2005
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Science Interactive LTD Copyright 2005
Types of energyTypes of energyEnergy cannot be destroyed or created, it can only be transformed from one type to another using a d_________. Energy is measured in joules, for example a 60 watt light bulb uses 60
joules of electrical energy per second. A kit Kat contains about 900 kilojoules of c___________ energy. There are eight forms of energy .Energy types: Word bank: device chemical
______________ ? ______________ ?
______________ ? ______________ ?
______________ ? ______________ ?
______________ ? ______________ ?
Examples
Diagram
ElasticChemicalSoundHeatType
London eye ______________ ?
Kinetic
Light bulb ______________ ?
______________ ? ______________ ?
______________ ? ______________ ?
Examples
Diagram
Type Electrical Gravitational Light
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Science Interactive LTD Copyright 2005
Energy and the jouleEnergy and the joule oneoneEnergy is measured in units called joules . Using joules allows you to compare how muche_________ in joules, something uses per second ( e.g. a light bulb ) or contains ( e.g. chocolate
bar .) The joule is a very small unit of energy. For example; to lift a 100 g weight, one metreabove the Earths surface , one joule of energy is used. Compare this to the energy contained ina Kit Kat which is approximately 900 kilojoules or 900,000 joules. That means to burn off theenergy in one Kit Kat, you would have the lift the 100 g weight one metre above the Earths
surface a mere 900,000 times !Energy and the joule: Word bank: energy
A 900 watt hairdryer will use 900 joules of electrical energy per
second. How many joules would thishairdryer use in oneminute ?
Hairdryer
A burger meal with friesand a sugary fizzy drink supplies almost 5000 kJ.
This is just under half thekilojoules you require for a whole day. Why is junk
food linked to obesity ?
A Kit Kat bar weighing just 50 grams contains900 kJ. If your daily
allowance is 12,000 kJ,how many kit kats can youeat to fulfil you dailyrequirements ?
A 60 watt bulb uses 60 joules per second a100 watt, 100 joules
per second. How muchwould a 100 watt light bulb use in 1 second, 5
seconds and 1 hour ?
Notes
Diagram
Bulb Chocolate Burger meal
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Science Interactive LTD Copyright 2005
Energy and the jouleEnergy and the joule twotwoThe power rating of an appliance tells us the number of joules that it uses every secondand the overall p________ of the appliance. If you were choosing between a 300 watt and500 watt drill, you might choose the 500 watt drill if you had to drill through concrete.This is because the strength of the drill will be higher, therefore the 500 watt drill would
be more able to drill very hard concrete. Below are some examples of the power ratingsand the energy (Js -1) that these devices use, every second. Try looking for the power rating
of your computer and play station at home ? (found underneath or rear of the product)
Energy and the joule: Word bank: power
A hearing aid, one of thesmallest electrical devicesrunning off small watch
batteries uses only 0.0001 joules per second.
Hearing aid
A hair dryer has a power rating of 900watts and uses 900
joules of electricalenergy per second.
Hair dryer
Notes
Diagram
A city that has a population of about tenmillion people usesabout 30,000 million
joules per second.
City
A new born babyweighing just 6 kg andtaking their fist stepsuses about 25 joules per second.
Baby
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Sc e ce te act ve D Copy g t 005
Energy and the jouleEnergy and the joule threethreeThe table below demonstrates the energy in joules involved in different events, fromthe k________ energy of a moving alpha particle to the energy received in solar energy by Earth from the Sun : Remember that 1 kilojoule is equal to 1000 joules .
Comparing energy:10 -11 kJ 10 -6 kJ 10 -1 kJ 1 kJ 10 3 kJ
10 7 kJ 10 13 kJ 10 17 kJ 10 20 kJ 10 25 kJ
Word bank: kinetic
Energy received fromthe Sun in one year
Energy release from anuclear bomb
Energy used by the shuttlegoing into orbit
Energy contained inone litre of petrol
Event
Diagram
Energy(kJ)
Energy used by thehuman body for 1 day
Energy from a burntmatch
Energy required to lift a100 g weight
Kinetic energy of analpha particle
Event
Diagram
Energy(kJ)
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py g
Energy use by the human bodyEnergy use by the human bodyAn adult human (male) body requires about 10,500 kJ every day. This value can varydepending on your s____, whether youre pregnant, your job and the sports you play.
Men require more energy than women because of their larger bodies. Teenagers usuallyrequire more energy during puberty, because they are growing and are usually moreactive. The highest demand for e________ is by women who are breastfeeding their newborns. Newborns only require about 25% of the energy of a fully grown adult. What
happens to your body weight if you consume too many kilojoules of food energy ?
Human energy use: Word bank: sex energy
A sleeping adult uses about 100 Joules per second which is the same as a 100 watt light bulb. Anewborn only uses about 25 Joules per second. When we run, walk or hurdle this increases our useof energy. Athletes normally consume much more energy in their diet when they are in training.
Notes
325 Joules per second
Hurdling
175 Joules per second
Walking
J/second
Diagram
100 Joules per second
Sleeping
300 Joules per second
Running
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Energy transformationsEnergy transformations oneone
___ joules of k_______ energy
1000 joules of electrical energy700 joules of heat and s________ energy.
45 joules of l_____ energy
100 joules of electrical energy
__ joules of heat energy
Energy can be transformed from one type to another by using a d________ like a bulb, motor or buzzer. During energy transformation, some useful energy can be lostto the environment. A simple device like a light bulb, for example transferse__________ energy to light and h______ energy. Only the light energy is usefulenergy, with the heat energy being lost to the environment. Work out the energytransfers when you a) light a firework, b) digest a Kit Kat & c) Burn wood ?
Energy transformations: Word bank: device electrical heat
A hairdryer transforms electrical energy into which forms of energy ?
Diagram A light bulb transforms electrical energy into which forms of energy ?
Diagram
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Energy transformationsEnergy transformations twotwo
300 joules of l_____ energy
1,000 joules of electrical energy
__ joules of heat energy
200 joules of l_____ energy
500 joules of electrical energy __ joules of heat energy
100 joules of sound energy
Most devices in the home use electrical energy. They are able to transform electricalenergy to other forms including, kinetic, heat, light and sound. Look at the following examples and complete the table ?
Energy transformations: Word bank: light heat
10 joules of light energy
300 joules of electrical energy
290 joules of h______ energy
A toaster converts electrical energy into which forms of energy ?
Diagram
A television transforms electrical energy into which forms of energy ?
Diagram
A light bulb transforms electrical energy into which forms of energy ?
Diagram
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hth
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60W
150W
150 J
120 J heat
30 J lightelectrical
50 J heat
electrical300 J kinetic
50 J sound
50 J heat
electrical300 J kinetic
50 J sound
electrical
150 J heat
500 J100 J
15 J sound
35 J light
Energy transfer diagrams show the relationship between the input energy and the output energy of adevice like a games console, vacuum cleaner and light bulb. During all energy transformations, some
energy is lost to the surroundings, for example a vacuum cleaner converts 500 joules of electricalenergy to 300 joules of kinetic energy and 200 joules to heat and sound energy. Only the kineticenergy is useful, with the heat and sound energy being lost to the surroundings. In the following examples, the useful energy is underlined.
Energy transformations:
Energy transformationsEnergy transformations threethree
Every second, a light bulbconverts 150 joules of electrical
energy into 120 joules of heatand 30 joules of light energy.The heat energy is lost to thesurroundings.
Every second, a Dyson converts 500 joules of electrical energy into 300
joules of kinetic energy, 50 joulesinto sound and 150 joules into heat.The heat and sound energy is lost tothe surroundings.
Every second, a games consoleconverts 50 joules of electrical
energy into heat, 15 joules intosound and 25 joules into light.This heat energy is lost to thesurroundings.
Notes
Light bulb (150 W)Dyson (500 W)
Transfer DiagramJs -1
Diagram
Console (100 W)
f d ff
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45 joules of l_____ energy
__ joules of heat energy
7500 kJ of e_______ energy
25 kJ of sound & light energy
75 kJ of heat energy
2500 kJ of heat energy
100 J of electrical
10,000 kJ of kinetic
100 kJ of electrical
Energy transformations and efficiencyEnergy transformations and efficiencyWhen energy is transformed into another form, some useful energy is lost to theenvironment or surroundings. The efficiency of a d_______ can be worked out usingthe following formula.
Energy transformations:
Energy efficiency = Useful energy out/total input energy x 100 (units %)
Word bank: device
Work out using the formula, the energyefficiency of a plasmatelevision ?
Three
Useful energy (red)
Work out using the formula, the energy
efficiency of a wind turbine ?
Two
One
Example Energy in Device
Calculation:45 J/100 J x 100= 45%
Energy efficiency
C d iC d iScience Interactive LTD Copyright 2005
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ConductionConductionHeat energy can be t___________ by conduction. When materials are heated, theatoms v_________ more. This kinetic energy can be passed from atom to atom in
conducting materials. Conduction happens in all materials, but in good conductorslike m_________, free electrons can transfer the heat energy more quickly. All metalsare good conductors of heat. Insulators do not have free e__________ and conductheat poorly. Explain why metals always feel cold to the touch, whereas wood for
example feels warm ?
Conduction: Word bank: transferred vibrating metals electrons
Direction of heat transfer
Hot Cold
In this picture, heat is conducted andtransferred by conduction. Heat energy
spreads out from the hot or warm regions(coloured in red) to colder regions(coloured in blue)
Conduction of heat energy
Heat energy is transferred by vibratingatoms passing on their kinetic energy to
adjacent atoms. Metals are good conductors because of their free electrons and highdensity.
Notes
Diagram
Conduction
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ConvectionConvectionHeat energy can be transferred through l_________ and gases by convection currents.Warm gases and liquids are less d________ because their vibrating atoms take up lessspace. This means that warm air or liquids rise to the surface. In a hot water tank, theelectric element heats the water which then rises to the top. As the warm water rises,the cooler water sinks making sure that all the water is heated. Convection currents donot transfer heat energy through solid materials...why ?
Convection:
Hot
Cold
Word bank: liquids dense
This thermographshows how hot
liquids (coloured inred) rise to thesurface in this pot.
Example one
The lava lamp firstmade in the 1960s
makes use of convection currentsto produce its effect.
Example two
As atoms are heated they vibrate moreand occupy more space. The less dense
gases or liquids rise to the top, cool thensink. Explain why in colds oceansnutrients are continuously recycled ?
Notes
Diagram
Convection
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R di tiR di ti
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RadiationRadiationHeat energy from the s____ and other hot objects can be transferred by radiation. Thistype of radiation is called infra red radiation and is part of the electromagneticspectrum. Infra red radiation can transfer energy through a vacuum and unlike heattransfer by c___________ or convection does not require a material to travel through.Although you cannot see this type of wave using your eyesight, your skin can feelinfra red because it has temperature receptors close to its surface. Why has your bodyevolved skin that can detected temperature changes ?
Radiation:
10 -2m 10 -4m 10 -6m
Infra red
Travels at 300,000 kms -1
Transfers energy
Travels through a vacuum
e.m. spectrum
The human body is
also a source of infrared radiation. Look at the above image !
Example two
All hot objects
emit heat as infrared radiation. Doesice emit infra red ?
All hot objects emit infra red radiation.
The Sun is the biggest source of infra redradiation. Over 10 23 kilojoules of heatenergy falls ontheEarths surface per year.
Notes
Diagram
Radiation Example oneWord bank: sun conduction
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S f gSo rces of energ
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Sources of energySources of energyThere are two types of energy: Renewable and non renewable forms. Non renewable
fossil fuels like coal, natural gas and o_____ are rich in the element c_______, can becombusted with oxygen, producing energy in the form of h____. They are fossil fuels
because they are formed from once living organisms. Remember that solar energy wasthe original e_______ source. Burning fossil fuels produces carbon dioxide which istermed a greenhouse gas ...Why ?
Main forms of fossil fuels: Word bank: oil carbon heat energy
30-40 years300 years60-70 yearsLifeexpectancy
Heating, Generating electricityHeating, generating electricityHeating, Transport, generating
electricity
Uses:
Found with crude oil deposits.Remains of dead plants.Remains of dead insects andother organic material.
Source
Natural gasCoalOilFuel
Diagram
Generating electrical energy from fossil fuelsScie
Generating electrical energy from fossil fuelsnce Interactive LTD Copyright 2005
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Generating electrical energy from fossil fuelsGenerating electrical energy from fossil fuelsCombusting fossil fuels like c_____, and natural gas produces h______ energy whichis used to produce super hot steam. The steam drives the turbines which are made
from huge magnets surrounded by a copper coil. The movement of the copper coilacross a magnetic field induces a c_________ flow in the copper wire. Electricalenergy cannot be stored and is delivered instantly by the National Grid using anetwork of overhead wires and underground cables clean and e fficiently to every
home in Britain.
Fossil fuels to electricity: Word bank: coal heat current
The amount of electricitythat you use during ayear is calculated using
meter readings. Theelectrical energy can betransformed into manyother forms of energy.
Customer
Electricity is thentransported along a hugenetwork of underground
or over ground copper cables to various usersincluding schools, homesand factories.
Transmission
Notes
Diagram
Non-renewable fossilfuels containing ancientenergy is extracted
from deep underground.These fuels includecrude oil, natural gasand coal.
Fuel
Combusting fossil fuelsgenerates large amountsof heat energy which in
turn boils water producing steam. Thisdrive turbines producingelectricity.
Power station
Renewable energy sourcesRenewable energy sourcesScience Interactive LTD Copyright 2005
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Renewable energy sourcesRenewable energy sourcesElectricity is very clean at the point of use, but combusting fossil fuels containingsulphur causes acid rain. Carbon dioxide, another pollutant from burning fossil fuels
traps heat in the atmosphere, therefore causing the g_____________ effect. Manysources of energy that we currently use every day are now renewable . This means thatunlike coal and natural gas they are not used up. Many scientists are working todevelop the technology to use these renewable sources of energy to generate
e___________. It is estimated that World consumption of energy is only a small fraction of the total energy received by Earth from the Sun every year.
Overview of renewable energy: Word bank: greenhouse electricity
Wind: Wind farms could supply up to 20% of the energy we use every year. Solar: Solar cells usingsolar energy could power traffic lights and street lamps. Geothermal: This type of energy is onlyfound in certain volcanic areas like Iceland. Biogas: Biogas converts animal waste like manure fromfarms into methane using microbes. Hydroelectric: Using moving water, hydroelectric dams are ableto generate clean electricity.
Notes
BiomassGeothermal
Diagram
Wind Solar Hydroelectric
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Hydroelectric powerHydroelectric power
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Hydroelectric power Hydroelectric power Hydroelectric dams use water to store g____________ potential energy. When the water isreleased by giant flood gates, the kinetic energy of moving water drives turbine generator
blades. As in other power stations, a current is induced and electricity is fed into the National Grid . Although this is a renewable c______ source of energy, the initial impactof constructing a dam and flooding the valley and surrounding areas is huge. Naturalhabitats and local biodiversity are often sacrificed for renewable energy. Not all areas are
suitable for hydroelectricity...explain why ?
Hydroelectric power:
Water stored behind the dam is releasedconverting gravitational potential energy to
kinetic energy and finally electrical energy.What type of weather conditions are required to make building dams economic ?
Generating electricity using water
Great barriers like theone picture above are
also used to controlflooding and generateelectricity.
The Hoover Dam builton the Colorado River
generates over onemillion kilowatts a dayof clean energy.
Notes
Diagram
Hoover dam Barrage dam
Word bank: gravitational clean
Biogas and biomassBiogas and biomassScience Interactive LTD Copyright 2005
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Biogas or m________ ( CH 4) is produced by fermenting organic matter like plant andanimal waste. M________ feeding on animal waste material (manure) produces methane
as a by product. This can be stored and used just like natural gas. Ethanol can also be usedas an alternative fuel source in cars. Sugarcane is grown, the sugar is extracted and thenfermented using y_________. The ethanol is then distilled and used just like p_________ and diesel in cars. In Brazil, 25% of all cars run off ethanol. Why does Britain not grow
sugarcane to produce ethanol ?
Producing ethanol and biogas:
Biogas and biomassBiogas and biomass
Word bank: methane micobes yeast petrol
et hanol e t h
a n
o l et hanol
e t h
a n
o l
Animal waste, like horse manure is used by bacteria to produce biogas. This is identical
to natural gas. Unlike natural gas which is afossil fuel, it can be produced over and over again.
Sugarcane is grown using large amounts of land in hot climates. The sugar is converted to
ethanol using yeast. Ethanol performs just aswell as petrol and reduces exhaust pollutantslike sulphur and carbon monoxide.
Notes
Diagram
Animal waste BiogasSugarcane Ethanol
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Tidal powerTidal power
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Tidal power Tidal power Tides and waves cause local water levels to r______ and fall. A barrage dam trapsw_______ at high tide. When the tide goes down again, the water can be released. The
flowing water turns the turbine generators to generate e_____________. As withhydroelectric dams, flooding can lead to the loss of habitats for many species that livealong river estuaries. Offshore underwater turbines ( wave generators ) can also use the riseand fall of water caused by waves or tides to generate electricity. Why is this a good choice
for renewable energy for countries like England ?
Energy from waves: Word bank: rise water electricity
Offshore wave generators like those pictured above,have little or no impact on the environment unlike
barrage dams. The turbine blade is turned bymoving water, which in turn generates an electriccurrent.
Kinetic energy of moving water isshown by this picture. Wave energy ishighest during the winter months.What causes waves in the seas and oceans ?
Notes
Diagram
Kinetic energy from waves Offshore wave electricity generators
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Geothermal energyGeothermal energy
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Geothermal energyGeothermal energyWhere the Earths crust is thin or where it contains large amount of radioactive substanceslike Uranium 235 a ready heat source from hot rocks is available. Water can be
superheated producing s_______. Inside a geothermal power station, steam turns a turbinewhich generates electricity. If the water temperature is lower, it can be used to h______
peoples homes. Iceland has many hot springs and volcanic regions and make use of itsnatural geothermal energy. Iceland has so much geothermal energy that residents receive
free heating and electricity for their homes !
Geothermal energy:
A natural sources of steam which drives turbines
capable of producing electricity. Pipes that go deepunderground deliver either steam for generators or hot water for home heating.
The outflow of this geothermal power
station in Iceland has become a touristresort ideal for hot bathing It isknown as the blue lagoon.
Notes
Diagram
Geothermal energy in Iceland Geothermal energy generating electricity
Word bank: steam heat
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Renewable wind powerRenewable wind power
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Renewable wind power Renewable wind power Pressure differences in the Earths atmosphere causes winds that blow across countries andcontinents. Wind is moving air that has k_________ energy. This energy can be used or
captured to drive a wind turbine generator . The blades are turned by the wind, which inturn makes a generator turn. This induces an electric current. Wind generators or farms arefound in w________ places like offshore or in mountainous areas. Although these windfarms dont create pollution, many people object to how they spoil the view. Are these
people justified in their views or should we continue to burn fossil fuels in order to generate our electricity ?
Wind energy: Word bank: kinetic windy
Wind farms are usually located offshore to avoid visual andnoise pollution. Also wind speeds are higher away fromland. Wind generators like the one pictured above will beused more and more in the future. Each one generatessufficient energy for around 1000 homes.
A single hurricane expends up to 10 15 kiloJoules during its short life. The governmentswant about 20% of the UK electricity to begenerated this way. It is clean, renewableand relatively cheap.
Notes
Diagram
Hurricane Wind farms and inside the wind turbine
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Cost of electrical energyCost of electrical energy
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Cost of electrical energyCost of electrical energyIn all homes supplied with electricity, a meter records how many u_______ of electricity you have used. The current cost of electricity is about 5 pence a kilowatt hour (kWh.) This cost is only an average cost, with electricity generated from somesources like solar and n________ power costing much more. Using electricity fromhydroelectric dams and burning fossil fuels like natural gas costs much less. You cannow choose to have only green electricity supplied to your house at a cost of 10
pence a kWh. What supplies green electricity and why does it cost most than other sources like fossil fuels ?
Overview of energy costs: Word bank: units nuclear
Each method of generating electrical energy has its advantages and drawbacks. Considering,cost, pollution, ease of use and cost of set up which is the best method of producing electricity ?
Notes:10 pence
Nuclear
2 pence
Hydroelectric
5 pence10 pence16 pence4 penceCost/kWh
Biogas
Diagram
Wind Solar Fossil fuels
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Energy use in the homeEnergy use in the home
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Energy use in the homegyEnergy supplied to homes, schools, hospitals and industry needs to be immediate and reliable .The national grid supplies electrical energy at the flick of a s_________. Demand for electrical
energy varies during the day, with peak demand in the morning and during working hours. Thelowest demand is during the n________. Power companies use reliable sources of energy likenuclear power to maintain a steady supply. When the demand is high, they can use energy
produced by gas fired or hydroelectric power stations. These can be started relatively quickly
and cope with peak demands . When are these peak periods likely to occur ?
Electricity use in the home: Word bank: switch night
The percentage of energy used in homes, offices and other building varies over the year. In thewinter the majority of energy is used for home heating and lighting. In the summer there isless demand because of the warm temperatures and long light evenings.
Notes:
4%
Cooking
7%42%47%
Diagram
Heating Lighting Other
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Saving energy about the homeSaving energy about the home oneone
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g gyg gySaving energy makes good sense: It costs you less money , uses up less fossil fuels andreduces p________ of the environment. Both at work and at home, we can all save energy.
Modern buildings are fitted with loft and wall insulation and double gazing. Theseinnovations help reduce heat e________ escaping through windows, doors, walls andceilings. Although fitting insulation and double glazing in older homes can be expensive,the money you save on heating bills will eventually repay the initial cost of installation.
Saving energy about the home one Word bank: pollution energy
Insulating the cavities between your walls isthe most effective typeof insulation, reducingenergy lost from2,600Js -1 to 1,000 Js -1.
Wall insulation
Placing insulation foamunderneath carpets, tilesor wooden floorsreduces energy loss by40% from 1200 Js -1 to700 Js -1.
Fitting double glazingreduces energy loss byhalf from 900 Js -1 to450Js -1. Explain howwindow double glazing works ?
About 1500 Joules of energy is lost everysecond through theroof. Using insulationcuts this down to about500 Js -1.
Notes
Diagram
Loft insulation Double glazing Floor insulation
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Saving energy about the homeSaving energy about the home twotwo
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g gyg gySaving energy is not just about reducing the amount of heat energy that e________ through the walls, floors, w_________ and loft. We can also use energy efficient devicesand a bit of common sense. Normal light bulbs are energy inefficient because they also
produce h______ energy. Energy efficient light bulbs use a fraction of the energy, but areable to produce the same amount of light. Common sense also plays a large part. Turningoff lights, boiling less water and wearing warm cloths indoors also saves energy and
reduces the amount of f_________ fuels that we use.
Saving energy about the home two Word bank: escapes windows heat fossil
Boiling a full kettle tomake a single cup of coffee wastes energy.Many modern kettlescan now boil a singlecup.
Boiling less water
Indoors, instead of turning up the heatingyou can wear a jumper.Reduce energy wastage
by closing doors andwindows.
At night, in any city or town, count the number of office buildings thatleave their lights on. Do
you do the same in your own house ?
Energy efficient bulbsuse only 12 wattscompared to normallight bulbs which useupto150watts. Explainthe difference ?
Notes
Diagram
Light bulbs Turning off lights Wear clothing
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Saving energy at homeSaving energy at home
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g gyg gy
2600 Js -1
900 Js -1
Heat loss though the floor
Heat loss through the roof
Heat lossthrough windows
Heat lossthrough wall
1 5 0 0
J s
- 1
1 2
0 0
J s
-1
Heating
Lighting
2.5
2.0
1.5
1.0
0.5
0.0Light bulb (100W)
Laptop (180W)
Toaster (900W)
Drill (1200W)
Hair dryer (1500W)
Kettle (2000W)
Heater (2500W) 2,500
2,000
1,500
1,000
500
0
W a t t
s K i l o w a t t s
2.5
2.0
1.5
1.0
0.5
0.0Light bulb (100 W)
Laptop (180 W)
Toaster (900 W)
Drill (1200 W)
Hair dryer (1500 W)
Kettle (2000 W)
Heater (2500 W) 2,500
2,000
1,500
1,000
500
0
W a t t s
K i l o w a t t s
Energy use by different devices
Picture to the left is how energy is used and lost inan average home. Using the information above,work out how you can save energy at home. Think how you can save energy used for lighting and
heating. Also how can you reduce heat loss in your home, through the walls, windows, roof space and floors ?
Earths fossil fuels are a finite resource and we can all do our bit to reduce the amount of energythat we consume at home or in the office. New houses are required to be energy e__________ withloft and wall insulation, efficient gas boilers and double glazing. How we live and respect the Earthsresources is important. Just switching off l_______ bulbs, reducing the central heating or not leavingour computer running saves energy and of course money. You can also opt to use renewable energy
purchased from your electricity supplier.
Saving energy at home: Word bank: efficient light
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Cars of the futureCars of the future ??
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Using h__________ fuel cells in cars and buses as an alternative to using petrol and dieselis now a real possibility. In 2003 London Buses took delivery of four buses than run usingthe reaction between hydrogen and oxygen producing w________ as a waste product.These buses cost over one million pounds each but reduce pollution to zero at the point of use. The hydrogen is supplied by splitting water using green electricity . In the very near future, all cars and buses could be using hydrogen fuel cells.
The hydrogen powered car: Word bank: hydrogen water
The car of the future ? Imagine your exhaust emitting only water. Not just
a distant dream but soon a realitywhen the costs of design andmanufacture comes down.
Hydrogen car
A current drives anelectric motor producing
movement. The surplusenergy can be stored in a
battery.
Hydrogen and oxygenfuses together forming
water as a waste liquid and power in the form of electricity.
Notes
Diagram
Hydrogen fuel cell How it works
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Extension questions and homework
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Direction of heat transfer
Hot Cold
1: Define the following terms: Energy, Device, Joule, Kilo-joules, Fossil-fuels, Efficiency & Renewable.
2: Look at the three pictures below. Complete the table.
3: Answer the following:
a) List three ways that heat energy can be lost from a house to the environment.
b) Explain how double glazing your house can reduce heat loss and your heating bill.
c) Explain how the air in expanded polystyrene coffee cups helps keep your coffee warm.
d) How does a foil blanket keep you warm and protect you from hypothermia.
e) How does a thermos flask keep your drink warm.f) Which saves more money: Double glazing or loft insulation.
g) Two houses: One with snow still on the roof, one without. Which is the most energy efficient house and why.
How is energy transferred ?
Radiation
Convection
Conduction
ExamplesTransfer method
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4: Look at the information in the table below. Answer the questions:
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a) Work out the pay back period for each method of insulating your house.
b) Which is the most cost effective method of saving energy.
c) Why does it take so long to recoup the cost of double glazing your home.
d) Why does loft insulation save most energy and money.
d) Think of two other methods for insulating your house.
5: a) Name four fossil fuels and four renewable sources of energy.
b) Explain how burning fossil fuels increases the (i) the greenhouse effect & (ii) acid rain.
c) Place these fuels in order, starting with the one that produces most carbon dioxide: Coal, Oil, Gas, Petrol.
d) Why are solar cells not suitable for generating high current electricity for large towns and cities.
e) Why is green electricity more expensive than energy generated by burning fossils fuels.e) Give two ways in which the following may damage and benefit the environment.
(i) Hydroelectric dams (ii) Solar cells (iii) Hydrogen fuel cell cars (iv) Biogas (v) Wind farms (vi) Geothermalenergy.
HighHigh (195)Moderately expensive (2450)Wall insulationHighHigh (250)Inexpensive (450)Loft insulation
Low (150)
Saving each year
LowExpensive (8000)Double glazing
Cost effectivenessInitial costInsulating method
Internet:Go to google.co.uk and find about how the combustion of fossils fuels produces acid rain and the greenhouse effect.Also find out about cars and buses powered by hydrogen fuel cells.