Revision of P1 Learning Objective: Recap all of the physics content with past paper questions

Index Topic Slide numbers Kinetic particle theory 3-14 Transfer of energy 15-29 Heat and the home 30-36 Energy efficiency 37- 55 Generating electricity 56-65 Cost of electricity 66-75 Waves 75-101 Origins of the Universe 102-114 REVISION OF P1

Kinetic particle theory Learning Outcomes: Good- know the key facts in the physics module EBI- You can apply what we recap to past paper questions Excellent- You can get 75% of marks in each question Kinetic particle theory The next few slides will give you all of the information that you need for a question about kinetic particle theory. Make sure you make a note of anything that you’re not sure of KINETIC PARTICLE THEORY

Translate KINETIC PARTICLE THEORY Learning Outcomes: Good- know the key facts in the physics module EBI- You can apply what we recap to past paper questions Excellent- You can get 75% of marks in each question Translate You are going to see 3 slides with information about the 3 states of matter. Translate the information you see into your own words, so that you will be able to remember all of the key facts. KINETIC PARTICLE THEORY Give students 2 minutes per slide to translate the information into their own words. The slides should automatically change after the 2 minutes is up

solids KINETIC PARTICLE THEORY Particles vibrate in a fixed position Learning Outcomes: Good- know the key facts in the physics module EBI- You can apply what we recap to past paper questions Excellent- You can get 75% of marks in each question solids Particles vibrate in a fixed position Strong bonds between particles Particles are close together Regular pattern in the arrangement Solids can’t be compressed as the particles have no space to move into and they have a fixed shape as the particles can’t move from place to place KINETIC PARTICLE THEORY Give students 2 minutes per slide to translate the information into their own words. The slides should automatically change after the 2 minutes is up

liquids KINETIC PARTICLE THEORY Learning Outcomes: Good- know the key facts in the physics module EBI- You can apply what we recap to past paper questions Excellent- You can get 75% of marks in each question liquids Particles vibrate and move around each other Weaker bonds between particles Particles are close together in a random arrangement Liquids can’t be compressed as the particles have no space to move into but they can change their shape to match the container that they are in as the particles can move around each other KINETIC PARTICLE THEORY Give students 2 minutes per slide to translate the information into their own words. The slides should automatically change after the 2 minutes is up

gases KINETIC PARTICLE THEORY Particles move quickly in any direction Learning Outcomes: Good- know the key facts in the physics module EBI- You can apply what we recap to past paper questions Excellent- You can get 75% of marks in each question gases Particles move quickly in any direction No bonds between particles Particles are far apart Random pattern in the arrangement Gases can be compressed or squashed as they have plenty of space to move into. They also flow and completely fill their container as their particles move quickly in all directions. KINETIC PARTICLE THEORY Give students 2 minutes per slide to translate the information into their own words. The slides should automatically change after the 2 minutes is up

Learning Outcomes: Good- know the key facts in the physics module EBI- You can apply what we recap to past paper questions Excellent- You can get 75% of marks in each question Kinetic theory Examiner’s tip Be able to describe the arrangement and movement of particles in solids, liquids and gases KINETIC PARTICLE THEORY Questioning – get them to think about what the examiners may ask of them and have a rally robin of what key points they’ll need to include in possible questions

Past paper question KINETIC PARTICLE THEORY solid gas solid Get them to write the answer to the questions on their wipe boards solid gas solid

Past paper question KINETIC PARTICLE THEORY Get them to write the answer to the questions on their wipe boards The marbles model act as molecules / atoms Molecules leaving a liquid = evaporation OR marbles leaving tray = evaporation

Past paper question KINETIC PARTICLE THEORY To evaporate the alcohol requires energy This energy (heat) is taken from the skin and the skin feels cold Get them to write the answer to the questions on their wipe boards

Past paper question KINETIC PARTICLE THEORY Get them to write the answer to the questions on their wipe boards

Past paper question There are attractive forces between molecules. Only the fastest molecules have enough energy to break away from other molecules. These molecules escape from the surface of the liquid. Therefore the average speed / energy of the remaining molecules goes down. The lower the average speed / energy of molecules the lower the temperature of the liquid. KINETIC PARTICLE THEORY

PROGRESS CHECK KINETIC PARTICLE THEORY Learning Outcomes: Good- know the key facts in the physics module EBI- You can apply what we recap to past paper questions Excellent- You can get 75% of marks in each question PROGRESS CHECK KINETIC PARTICLE THEORY Get them to add key information about kinetic particle theory to their mind map

Quick note TRANSFER OF ENERGY Quickly jot down any information that you do not know from the next 8 slides. If you are happy with the information, try and change it into a maximum of 3 sentences TRANSFER OF ENERGY

Conduction – key facts DO NOT COPY ALL OF THIS TRANSFER OF ENERGY Metals are good conductors Non-metals and gases are poor conductors Free electrons are able to move about in metals and the part of the metal atoms that are left behind are charged metal ions These metal ions are packed closely together and vibrate all the time The hotter the metal, the faster the vibrations of the ions This kinetic energy is then transferred from the hotter parts of the metal to the cooler parts of the metal by the free electrons as they collide with the ions as they move about TRANSFER OF ENERGY The slides should automatically change after the 2 minutes is up

Convection – key facts DO NOT COPY ALL OF THIS TRANSFER OF ENERGY Liquids and gases are fluids When they are heated, they expand as the particles move faster The liquid or gas then becomes less dense as the particles take up more space but they are still the same size The liquid or gas in hot areas is less dense than the liquid or gas in cold areas, so it rises into the cold areas. The denser cold liquid or gas falls into the warm areas. This cycle continues until the heat source is removed The wind is caused by convection currents from the Earth being heated by the sun TRANSFER OF ENERGY The slides should automatically change after the 2 minutes is up

Radiation – key facts DO NOT COPY ALL OF THIS TRANSFER OF ENERGY All objects emit (give out) and absorb (take in) thermal radiation (infrared radiation) The hotter the object, the more infrared radiation given off Infrared radiation is a type of EM radiation so it travels in waves and can travel in a vacuum Dark, matt materials are good absorbers and emitters of infrared radiation Light, shiny materials are poor absorbers and emitters of infrared radiation TRANSFER OF ENERGY The slides should automatically change after the 2 minutes is up

Evaporation – key facts DO NOT COPY ALL OF THIS The particles in a liquid have different energies Some will have enough energy to escape from the liquid and become a gas. The remaining particles in the liquid have a lower average kinetic energy than before, so the liquid cools down as evaporation happens. This is why sweating cools you down. The sweat absorbs energy from your skin so that it can continue to evaporate. TRANSFER OF ENERGY The slides should automatically change after the 2 minutes is up

Condensation – key facts DO NOT COPY ALL OF THIS The particles in a gas have different energies. Some may not have enough energy to remain as separate particles, particularly if the gas is cooled down. They come close together and bonds form between them. Energy is released when this happens. This is why steam touching your skin can cause scalds: not only is the steam hot, but energy is released into your skin as the steam condenses. TRANSFER OF ENERGY The slides should automatically change after the 2 minutes is up

Factors affecting condensation and evaporation – key facts DO NOT COPY ALL OF THIS Condensation happens faster if the temperature of the gas is lowered Evaporation happens faster if the liquid is increased. Evaporation happens faster if the surface area is increased Evaporation happens faster if air is moving over the surface of the liquid TRANSFER OF ENERGY The slides should automatically change after the 2 minutes is up

Factors affecting heat transfer key facts DO NOT COPY ALL OF THIS Bigger temperature difference -> the faster the heat transfer Larger surface area -> the faster the heat transfer Larger volume -> the faster the heat transfer Some materials either increase / decrease heat transfer TRANSFER OF ENERGY The slides should automatically change after the 2 minutes is up

Heat transfer in action DO NOT COPY ALL OF THIS Small animals have a large surface area to volume ratio so the lose heat quickly Large animals have a low surface area to volume ratio so lose heat slowly Arctic fox has small ears to lose heat slowly Fennec fox has large ears to lose heat quickly Car radiators are flat with many fins so they lose heat quickly Household radiators are thin, flat, sometimes with fins, in order to give heat to the room quickly TRANSFER OF ENERGY The slides should automatically change after the 2 minutes is up

PROGRESS CHECK TRANSFER OF ENERGY Learning Outcomes: Good- know the key facts in the physics module EBI- You can apply what we recap to past paper questions Excellent- You can get 75% of marks in each question PROGRESS CHECK TRANSFER OF ENERGY Get them to add key information about transfer of energy to their mind maps

TRANSFER OF ENERGY Get them to write the answer to the questions on their wipe boards Energy needed to produce evaporation comes from the body This stops the body temperature rising

Past paper question TRANSFER OF ENERGY The silver space blanket reflects energy back to the runner This reduces the energy transferred from the body by radiation Get them to write the answer to the questions on their wipe boards

transfer of energy by waves / infrared Get them to write the answer to the questions on their wipe boards Ions gain kinetic energy Energy is transferred to cooler parts of the metal by free electrons

Water particles at the bottom are heated Water particles move faster The warmer water expands (becomes less dense) The warm water rises / cold water falls to take its place TRANSFER OF ENERGY Get them to write the answer to the questions on their wipe boards

Examiner's TIPS TRANSFER OF ENERGY Know that air is an excellent insulator and examples of insulation materials using trapped air. Be able to explain why evaporation causes the surroundings to cool. Know the factors affecting the rate at which an object transfers energy by heating and applications of this. Know how the nature of a surface affects the amount of infrared emitted. Understand the difference between an object emitting infrared radiation and absorbing infrared radiation. TRANSFER OF ENERGY Use red, amber and green cards to show confidence in the examiner’s tips

HEAT AND THE HOME HEAT AND THE HOME In order to save money, people can change the materials used in housing. E.g. The materials used for their windows Energy-saving solutions cost money to buy and install. The payback time of an energy-saving solution is a measure of how cost-effective it is. Here is the equation to calculate payback time: Payback time (years) = cost of installation (£) ÷ savings per year in fuel costs (£) If the payback time is too long, the energy-saving solution is not cost-effective HEAT AND THE HOME

Heat AND THE HOME Specific heat capacity of materials can be found by using the formula: E = m × c × ө This tells us how much energy is needed to increase the temperature of 1kg by one degree Celsius The higher the specific heat capacity, the more energy the material can store (e.g. water) Materials have a U-value which tells us how well heat travels through a material The lower the U-value, the better it is at insulating HEAT AND THE HOME

HEAT AND THE HOME Get them to write the answer to the questions on their wipe boards

HEAT AND THE HOME 1 3 and 4 OR 1 and 2 Get them to write the answer to the questions on their wipe boards U-values for the 20 mm windows are the same or higher than those for the 16 mm windows So the 20 mm windows are no more energy efficient than 16 mm windows

HEAT AND THE HOME Get them to write the answer to the questions on their wipe boards 1 and 2

HEAT AND THE HOME Get them to write the answer to the questions on their wipe boards Type B glass transmits less infrared than Type A glass As infrared has a heating effect the conservatory will remain cooler

Examiner's TIPS HEAT AND THE HOME Know that air is an excellent insulator and examples of insulation materials using trapped air. Be able to explain why evaporation causes the surroundings to cool. Know the factors affecting the rate at which an object transfers energy by heating and applications of this. Know how the nature of a surface affects the amount of infrared emitted. Understand the difference between an object emitting infrared radiation and absorbing infrared radiation. HEAT AND THE HOME Use red, amber and green cards to show confidence in the examiner’s tips

Energy efficiency Most Kids Hate Learning GCSE Energy Names Magnetic Kinetic (movement energy) Heat (thermal energy) Light Gravitational potential Chemical Sound Electrical Elastic potential Nuclear ENERGY EFFICIENCY Get them to give an example of a source of each type of energy type

Energy efficiency ENERGY EFFICIENCY Wasted Input Useful Get them to state the energy transfers in each of the pictures on their wipe boards Input – electrical Wasted – heat Useful – sound and light Useful

Energy efficiency ENERGY EFFICIENCY Wasted Input Useful Get them to state the energy transfers in each of the pictures on their wipe boards Input – electrical Wasted – sound and heat Useful - kinetic Useful

Energy efficiency ENERGY EFFICIENCY Wasted Input Useful Get them to state the energy transfers in each of the pictures on their wipe boards Input – chemical Wasted – heat and sound Useful - kinetic Useful

ENERGY EFFICIENCY ENERGY EFFICIENCY Wasted Input Useful Get them to state the energy transfers in each of the pictures on their wipe boards Input – chemical Wasted – heat Useful – kinetic and sound Useful

ENERGY EFFICIENCY ENERGY EFFICIENCY Wasted Input Useful Get them to state the energy transfers in each of the pictures on their wipe boards Input – electrical Wasted – heat Useful - light Useful

Sankey Diagram ENERGY EFFICIENCY The thickness of each arrow is drawn to scale to show the amount of energy ENERGY EFFICIENCY

Sankey Diagram ENERGY EFFICIENCY Notice that the total amount of energy before is equal to the total amount of energy after (conservation of energy) ENERGY EFFICIENCY

Efficiency ENERGY EFFICIENCY Although the total energy out is the same, not all of it is useful. ENERGY EFFICIENCY

Efficiency ENERGY EFFICIENCY Efficiency is defined as Efficiency (%) = useful energy output x 100 total energy input The closer the efficiency is to 1 or 100%, the more efficient the device is and the less energy it wastes No device will have an efficiency of 1 or 100% as some energy is always lost as heat to the surroundings ENERGY EFFICIENCY

Example Efficiency = 75 x 100 = 15% 500 ENERGY EFFICIENCY

Why do you think this is a good thing? Why use energy efficient devices? We need to use energy efficient devices as they use less energy to do the same job when compared to less energy efficient devices. Why do you think this is a good thing? ENERGY EFFICIENCY 1. Save money 2. Less energy resources are used so there will be more for the future 3. Less CO2 is produced so the effect of global warming will be decreased

Past paper question ENERGY EFFICIENCY 120 / 200 = 0.6 or 60% Get them to write the answer to the questions on their wipe boards 120 / 200 = 0.6 or 60%

Past paper question ENERGY EFFICIENCY More efficient, so less energy / electricity needed Less fuel burned so less CO2 produced ENERGY EFFICIENCY Get them to write the answer to the questions on their wipe boards You could turn the sound up or down You could turn the brightness up or down

ENERGY EFFICIENCY Get them to write the answer to the questions on their wipe boards Most energy out as light or least energy wasted as heat

ENERGY EFFICIENCY 22 28 / 50 * 100 = 56% 14 squares 25 squares Get them to write the answer to the questions on their wipe boards 28 / 50 * 100 = 56%

ENERGY EFFICIENCY Energy = power × time Power = 0.85 kW, time = 0.1 kWh Get them to write the answer to the questions on their wipe boards

PROGRESS CHECK ENERGY EFFICIENCY Learning Outcomes: Good- know the key facts in the physics module EBI- You can apply what we recap to past paper questions Excellent- You can get 75% of marks in each question PROGRESS CHECK ENERGY EFFICIENCY Get them to add key information about energy efficiency to their mind maps

Energy efficiency Examiner’s tip Know how to use the equation and calculate the efficiency either as a decimal or as a percentage. Understand why a device or process can never be greater than 100% efficient. Understand the term ‘pay-back’ time in relation to heating and insulating buildings. ENERGY EFFICIENCY Questioning – get them to think about what the examiners may ask of them and have a rally robin of what key points they’ll need to include in possible questions

GENERATING ELECTRICITY 4 5 3 2 1 GENERATING ELECTRICITY Fossil fuel is burnt The heat turns water to steam The steam turns a turbine The turbine turns a generator This induces a current and creates electricity

GENERATING ELECTRICITY Electricity from a power station goes to: Step-up transformers – increases the voltage which decreases the current and reduces energy loss High voltage transmission lines Step-down transformers – decrease the voltage to make it safe for us to use Consumers, for example homes, factories and shops. GENERATING ELECTRICITY

Non-Renewable energy GENERATING ELECTRICITY All of these methods are used to heat water to create steam which is used to turn the turbine and generate electricity Energy source Advantages Disadvantages Coal Relatively cheap to mine, ready made fuels Non-renewable, burning produces CO2 Oil Short start-up time, ready made fuels Gas Slightly cleaner fuel than oil and gas and is a ready made fuel Nuclear power Produces lots of energy, does not produce CO2 Non-renewable, produces dangerous nuclear waste GENERATING ELECTRICITY Give students 2 minutes per slide to translate the information into their own words. The slides should automatically change after the 2 minutes is up

Renewable energy GENERATING ELECTRICITY Wind, hydroelectricity and geothermal all turn a turbine which will create electricity Solar cells use light to create electricity Energy source Advantages Disadvantages Wind Renewable, no fuel costs No wind sometimes, noisy Hydroelectric Can flood areas, disrupts habitats Solar No sun at night, some countries don’t get enough sun in the day, panels are expensive Geothermal Only available in volcanic regions, GENERATING ELECTRICITY Give students 2 minutes per slide to translate the information into their own words. The slides should automatically change after the 2 minutes is up

GENERATING ELECTRICITY Power stations fuelled by fossil fuels or nuclear fuels are reliable sources of energy. This means they can provide power whenever it is needed. gas-fired station (shortest start-up time) oil-fired station coal-fired station nuclear power station (longest start-up time) Nuclear power stations and coal-fired power stations provide 'base load' electricity - run all the time as they take the longest time to start up. Oil-fired and gas-fired power stations are often used to provide extra electricity at peak times, because they take the least time to start up. The fuel for nuclear power stations is relatively cheap, but the power stations themselves are expensive to build. It is also very expensive to dismantle old nuclear power stations and to store their radioactive waste, which is a dangerous health hazard. GENERATING ELECTRICITY Get them to read this statement and summarise this in a MAXIMUM of 25 words.

GENERATING ELECTRICITY Boiler Generator GENERATING ELECTRICITY Get them to write the answer to the questions on their wipe boards

GENERATING ELECTRICITY 6 squares 20 squares 14 squares GENERATING ELECTRICITY Get them to write the answer to the questions on their wipe boards Useful / input 6 / 20 = 0.3 or 30%

GENERATING ELECTRICITY Generator Get them to write the answer to the questions on their wipe boards Nuclear fission

PROGRESS CHECK GENERATING ELECTRICITY Learning Outcomes: Good- know the key facts in the physics module EBI- You can apply what we recap to past paper questions Excellent- You can get 75% of marks in each question PROGRESS CHECK GENERATING ELECTRICITY Get them to add key information about generating electricity to their mind maps

Examiner's TIPS Wave energy - the rise and fall of the water (kinetic energy) drives generators and makes electricity Tidal energy – when the tide goes in and out, there is a large amount of kinetic energy. This goes through a tidal barrage that contains generators which makes electricity Carbon capture and storage stops carbon dioxide building up in the atmosphere. It involves separating carbon dioxide from waste gases. The carbon dioxide is then stored underground, for example in old oil fields or gas fields. Be able to draw and label a block diagram of a power station showing the main parts. Be able to distinguish the difference between waves and tides. Be able to describe the advantages and disadvantages of solar cells. Understand that to prevent carbon dioxide building up in the atmosphere we can catch it and store it. Some of the best natural containers are old oil and gas fields. Be able to identify and label a diagram of the main parts of the National Grid. GENERATING ELECTRICITY Use red, amber and green cards to show confidence in the examiner’s tips

Learning Outcomes: Good- know the key facts in the physics module EBI- You can apply what we recap to past paper questions Excellent- You can get 75% of marks in each question Cost of electricity We can calculate the amount of electrical energy transferred by an appliance and how much it costs to run. This is useful for comparing the advantages and disadvantages of using different electrical appliances COST OF ELECTRICITY

Cost of electricity E = P × t E - energy transferred in kWh / J P - power in kW T - time in h. Power is sometimes measured in kWh. To convert from W to kW you must divide by 1,000. E.g. 2,000 W = 2,000 ÷ 1,000 = 2 kW. COST OF ELECTRICITY kWh – kilowatt hours kW – kilowatts h – hour J - Joule

Electricity meters measure the number of units of electricity used Electricity meters measure the number of units of electricity used. The more units used, the greater the cost. total cost = number of units × cost per unit E.g. if 5 units of electricity are used at a cost of 8p per unit, the total cost will be 5 × 8 = 40p The number of units used can be calculated using this equation: total cost = power (kW) × time (h) × cost per unit COST OF ELECTRICITY kWh – kilowatt hours kW – kilowatts h – hour J - Joule

PROGRESS CHECK GENERATING ELECTRICITY Learning Outcomes: Good- know the key facts in the physics module EBI- You can apply what we recap to past paper questions Excellent- You can get 75% of marks in each question PROGRESS CHECK GENERATING ELECTRICITY Get them to add key information about the cost of electricity to their mind maps

Examiner's TIPS COST OF ELECTRICITY Know the units of each term in the equation. Know how to convert power from watts to kilowatts and vice versa. Know how to convert time from hours to minutes and seconds and vice versa, and be careful to make these conversions in an exam if necessary. COST OF ELECTRICITY Use red, amber and green cards to show confidence in the examiner’s tips

Removal of exhaust gases Use alternative source not producing CO2 COST OF ELECTRICITY acid rain global warming/greenhouse effect Get them to write the answer to the questions on their wipe boards Removal of exhaust gases Use alternative source not producing CO2

COST OF ELECTRICITY E = 5 × 108 × 3600 × 24 J/day Get them to write the answer to the questions on their wipe boards E = 5 × 108 × 3600 × 24 J/day × 4 (for 4 generators) P × t = 1.73 × 1014 (J/day)

2.66 × 1010 × 18 829 = 4.86 × 1014 COST OF ELECTRICITY useful/input Get them to write the answer to the questions on their wipe boards useful/input 1.73/4.86 0.36 or 36%

COST OF ELECTRICITY boiler – heat to surroundings turbine – not all steam energy used/heat/sound lost to surroundings generator – heat in wires/coils/heat to surroundings transformer – heat in wires/coils/heat to surroundings COST OF ELECTRICITY Get them to write the answer to the questions on their wipe boards Energy spread out/diluted As surroundings become warmer/energy lost as heat

waves Waves are vibrations that transfer energy from place to place without matter (solid, liquid or gas) being transferred. Some waves must travel through a substance. The substance is known as the medium and it can be solid, liquid or gas. WAVES

TRANSVERSE waves In transverse waves, the oscillations (vibrations) are at right angles to the direction of travel and energy transfer Light and other types of electromagnetic radiation are transverse waves. All types of electromagnetic waves travel at the same speed through a vacuum, such as through space. WAVES

Longitudinal waves In longitudinal waves, the oscillations are along the same direction as the direction of travel and energy transfer. Sound waves and waves in a stretched spring are longitudinal waves. WAVES

Labelling waves The wavelength of a wave is the distance between a point on one wave and the same point on the next wave. The frequency of a wave is the number of waves produced by a source each second. It is also the number of waves that pass a certain point each second. WAVES

Wave equation The speed of a wave is related to its frequency and wavelength, according to this equation: v = f × λ v is the wave speed in metres per second, m/s f is the frequency in hertz, Hz λ (lambda) is the wavelength in metres, m. WAVES

Past paper question WAVES speed = frequency × wavelength Get them to write the answer to the questions on their wipe boards 300, 000,000 / 909 000 = 330m

A W W WAVES Get them to write the answer to the questions on their wipe boards 0.1m X 2Hz 0.2m/s

The angle of incidence equals the angle of reflection WAVES The angle of incidence equals the angle of reflection Sound waves and light waves reflect from surfaces. Smooth surfaces produce strong echoes when sound waves hit them, and they can act as mirrors when light waves hit them. The waves are reflected uniformly and light can form images

reflection WAVES Rough surfaces scatter sound and light in all directions. However, each tiny bit of the surface still follows the rule that the angle of incidence equals the angle of reflection

refraction Sound waves and light waves change speed when they pass across substances with different densities. This causes them to change direction and this effect is called refraction. Refraction doesn't happen if the waves cross the boundary at an angle of 90°(the normal) - they carry straight on. WAVES

diffraction When waves meet a gap in a barrier, they carry on through the gap and spread out How much they spread out depends on how the width of the gap compares to the wavelength of the waves. Lots of diffraction happens when the wavelength is the same size as the gap. WAVES

diffraction A gap similar to the wavelength causes a lot of spreading with no sharp shadow, e.g. sound through a doorway A gap much larger than the wavelength causes little spreading and a sharp shadow, e.g. light through a doorway. WAVES

Ray diagrams Sound waves and light waves change speed when they pass across substances with different densities. This causes them to change direction and this effect is called refraction. Refraction doesn't happen if the waves cross the boundary at an angle of 90°(the normal) - they carry straight on. WAVES

Past paper question WAVES The normal v Get them to write the answer to the questions on their wipe boards The normal v light has moved from glass to air / from air to glass

value of v doubles but the value of y does not double WAVES Get them to write the answer to the questions on their wipe boards value of v doubles but the value of y does not double

WAVES As (angle) v increases, angle y increases Get them to write the answer to the questions on their wipe boards no evidence outside this range

Sound WAVES Longitudinal waves Echoes are reflections of sound waves Sound can only travel in a solid, liquid or gas A loud sound has a high amplitude A quiet sound has a small amplitude A high pitched sound has a high frequency A low pitched sound has a low frequency The normal range of human hearing is between about 20 Hz and 20 kHz The range becomes less as we get older. Sounds with frequencies above about 20 kHz are called ultrasound. WAVES

Electrical vibrations Past paper question Microphone WAVES Loud speaker Get them to write the answer to the questions on their wipe boards Radio waves Electrical vibrations Light waves

Past paper question WAVES It will go quieter Get them to write the answer to the questions on their wipe boards

ELECTROMAGNETIC (em) SPECTRUM Contains 7 different types of radiation WAVES Longest wavelength Shortest frequency Shortest wavelength Highest frequency

radiowaves WAVES Used for TV and radio TVs use higher frequencies than radios Diffraction allows radio signals to be received behind hills and repeater stations are used to improve reception WAVES

microwaves WAVES Used to transmit signals such as mobile phone calls. Microwave transmitters and receivers on buildings and masts communicate with the mobile telephones in their range. Some mobile phones may be a health risk. Others think that the intensity of the microwaves is too low to damage tissues by heating, and microwaves are not ionising. Some wavelengths can be used to transmit information to and from satellites in orbit. Satellite TV signals use microwaves. WAVES

VISIBLE LIGHT AND INFRARED Visible light helps us to communicate via sight Cameras and video recorders use visible light Very bright light damages our eyes WAVES INFRARED Infrared is used in toasters, heaters and grills and can cause burns Used in burglar alarms, remote controls and security alarms

Examiner’s tip Be able to construct a ray diagram to show the image formed by a plane mirror. Know the order of the electromagnetic waves within the spectrum in terms of energy, frequency and wavelength. Be able to complete diagrams for wave fronts showing reflection, refraction and diffraction. Learn the units of the terms in the equation and know how to convert kilohertz to hertz. Know how radio waves, microwaves, infrared and visible light can be used in communications. Know the relationship between pitch and frequency. WAVES Questioning – get them to think about what the examiners may ask of them and have a rally robin of what key points they’ll need to include in possible questions

to compare mobile phone usage between the two groups Past paper question to compare mobile phone usage between the two groups WAVES Get them to write the answer to the questions on their wipe boards enough data to indicate relationship or reduce effect of anomalous data

Past paper question WAVES Get them to write the answer to the questions on their wipe boards

Past paper question WAVES Research may be biased (in favour of companies) Negative effects on health may not get published WAVES Get them to write the answer to the questions on their wipe boards It allows people to easily identify lower risk phones And this allows people to make a more informed choice

PROGRESS CHECK WAVES Learning Outcomes: Good- know the key facts in the physics module EBI- You can apply what we recap to past paper questions Excellent- You can get 75% of marks in each question PROGRESS CHECK WAVES Get them to add key information about waves to their mind map

Origins of the universe Learning Outcomes: Good- know the key facts in the physics module EBI- You can apply what we recap to past paper questions Excellent- You can get 75% of marks in each question Origins of the universe The next few slides will give you all of the information that you need for a question about the origins of the Universe. Make sure you make a note of anything that you’re not sure of ORIGINS OF THE UNIVERSE

Origins of the universe Learning Outcomes: Good- know the key facts in the physics module EBI- You can apply what we recap to past paper questions Excellent- You can get 75% of marks in each question Origins of the universe Examiner’s tip Be able to explain the term ‘red-shift’ and the ‘Big Bang’ theory. ORIGINS OF THE UNIVERSE Questioning – get them to think about what the examiners may ask of them and have a rally robin of what key points they’ll need to include in possible questions

The big bang ORIGINS OF THE UNIVERSE Theory – an idea but not a fact The theory states that originally all the matter in the universe was concentrated into a single incredibly tiny point. This began to enlarge rapidly in a hot explosion (called the Big Bang), and it is still expanding today. The Big Bang happened about 13.7 billion years ago ORIGINS OF THE UNIVERSE

Evidence for the big bang Cosmic microwave background radiation (CMBR) – thought to be left over heat from the original explosion Doppler effect Red-shift ORIGINS OF THE UNIVERSE

Explaining the Doppler effect When a police car goes past, its siren is high-pitched as it comes towards you, then becomes low-pitched as it goes away. When a source (e.g. galaxy) moves towards an observer, the observed wavelength decreases and the frequency increases. When a source (e.g. galaxy) moves away from an observer, the observed wavelength increases and the frequency decreases. ORIGINS OF THE UNIVERSE

Red-shift ORIGINS OF THE UNIVERSE When an object (e.g. galaxy) moves away from an observer, its light is affected by the Doppler effect We know our sun has helium in it because there are black lines in the spectrum of the light from the Sun where helium has absorbed light. These lines form the absorption spectrum for helium. When we look at the spectrum of a distant star, we still see an absorption spectrum. However, the pattern of lines has moved towards the red end of the spectrum, as you can see above. ORIGINS OF THE UNIVERSE

Red-shift ORIGINS OF THE UNIVERSE The positions of the lines have changed because of the Doppler effect. Their wavelengths have increased and their frequencies have decreased. The further from us a star is, the more its light is red-shifted. This tells us that distant galaxies are moving away from us, and that the further away a galaxy is, the faster it's moving away. Red shift tells us how far away a galaxy is and the speed at which it is getting further away from us ORIGINS OF THE UNIVERSE

Past paper question Distance from Earth ORIGINS OF THE UNIVERSE Distance from Earth Speed stars / galaxies are moving (away from Earth) Supports theory that the Universe is expanding / Big Bang theory Get them to write the answer to the questions on their wipe boards

Past paper question ORIGINS OF THE UNIVERSE The microwave radiation comes from radiation present just after Big Bang The Big Bang theory is currently the only way of explaining CMBR ORIGINS OF THE UNIVERSE Get them to write the answer to the questions on their wipe boards wavelength is decreased and frequency increased

Big bang theory – universe started at one point then expanded Steady state theory – universe has no origin / has always existed ORIGINS OF THE UNIVERSE Get them to write the answer to the questions on their wipe boards Wavelength of light increases / frequency of light decreases or wavelength / light moves to red end of spectrum

ORIGINS OF THE UNIVERSE Red-shift is evidence / supports idea of expanding universe Both theories use the idea / accept / explain why the universe is expanding to find evidence to support one or both theories or to find evidence to disprove one or both theories ORIGINS OF THE UNIVERSE Get them to write the answer to the questions on their wipe boards Religious belief or no / insufficient evidence

PROGRESS CHECK ORIGINS OF THE UNIVERSE Learning Outcomes: Good- know the key facts in the physics module EBI- You can apply what we recap to past paper questions Excellent- You can get 75% of marks in each question PROGRESS CHECK ORIGINS OF THE UNIVERSE Get them to add key information about origins of the universe to their mind map