Physics 1 Which key terms do I need

Physics 1 Which key terms do I need to remember?

How to use this powerpoint • This powerpoint covers all the material in the P 1 topic you studied in year 10 and will need to know for the physics part of your Science A exam at the end of year 11. • Each slide has a few key words taken out – see if you can complete the phrases and then check your answers against the next slide Look at a few slides every week, then try some of the questions from past papers on the AQA website : http: //www. aqa. org. uk/subjects/science/gcse/science-a 4405/past-papers-and-mark-schemes Good Luck!

States of Matter Solid Liquid Solid Particle arrangement Energy and movement Forces between particles Compressible? Liquid Gas

States of Matter Solid Liquid Gas Particle arrangement Close together; regular pattern Further apart Far apart; random arrangement Energy and movement Little energy; vibrate about fixed position More energy than solids; particles move freely Lots of energy; particles move quickly in all directions Forces between particles Strong Weak None Compressible? No No Yes

Transfer of Energy

Conduction 1. ………………. are good conductors and ………………… and ……………. are poor conductors. 2. In metals, ………… electrons move about …………………. . . They ……………… with each other and the positive ions. 3. When a metal rod is heated, the free electrons ……… and move faster. When they collide with the other electrons and ions ……………… energy is then transferred. 4. Non-metals are ………. . conductors because they do not contain free electrons.

Conduction 1. Metals are good conductors and non-metals and gases are poor conductors. 2. In metals, free electrons move about randomly. They collide with each other and the positive ions. 3. When a metal rod is heated, the free electrons gain energy and move faster. When they collide with the other electrons and ions kinetic energy is then transferred. 4. Non-metals are poor conductors because they do not contain free electrons.

Convection 1. Liquids and gases are …………. 2. A convection current: when liquids or gases are ………………, they ……………. . as the particles move faster. The liquid or gas then becomes ……………. as the particles take up more space. The liquid or gas in hot areas is less dense than the liquid or gas in cold areas, so it ………. into the cold areas. The denser cold liquid or gas falls into the warm areas.

Convection 1. Liquids and gases are fluids. 2. A convection current: 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. 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.

Radiation 1. Emit = Absorb = 2. Increasing temperature…… 3. Infrared radiation is 4. Good absorbers and emitters = 5. Poor absorbers and emitters =

Radiation 1. Emit = give out Absorb = take in 2. Increasing temperature results in more i. r. radiation being emitted 3. Infrared radiation is a type of electromagnetic radiation; travels in waves and can travel in a vacuum 4. Good absorbers and emitters = dark, matt surfaces 5. Poor absorbers and emitters = light, shiny surfaces

Evaporation and Condensation 1. Evaporation = 2. Condensation = 3. Evaporation is increased by: 4. Condensation is increased by:

Evaporation and Condensation 1. Evaporation = some particles have enough energy to escape from the surface of the liquid and turn into a gas. The remaining particles in the liquid have a lower average kinetic energy than before, so the liquid cools down as evaporation happens. 2. Condensation = gas → liquid. Energy is given out. 3. Evaporation is increased by: increasing the surface area or the liquid; increasing the liquid’s temperature; creating a draught 4. Condensation is increased by: increasing the surface area; reducing the temperature of the surface

Factors Affecting Heat Transfer There are 4 factors that increase the rate of heat transfer: 1. 2. 3. 4.

Factors Affecting Heat Transfer There are 4 factors that increase the rate of heat transfer: 1. Bigger temperature difference 2. Larger surface area 3. Larger volume 4. Type of material

Heating and Insulating Buildings 1. Heat energy can be lost from a house in a number of places: 2. Methods for reducing energy transfer: 3. Payback time (years) = If the payback time is too long, the energy-saving solution is not ………-………………

Heating and Insulating Buildings 1. Heat energy can be lost from a house in a number of places: loft; walls; doors; windows; roof 2. Methods for reducing energy transfer: loft insulation; cavity wall insulation; double glazing 3. 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.

Specific Heat Capacity 1. Specific heat capacity = 2. The ………. . the specific heat capacity, the ………… energy the material can store (e. g. water). 3. U-value = 4. The ………………. . the U-value, the ………………. . it is at insulating.

Specific Heat Capacity 1. Specific heat capacity of materials tells us how much energy is needed to increase the temperature of 1 kg by one degree Celsius. 2. The higher the specific heat capacity, the more energy the material can store (e. g. water). 3. Materials have a U-value which tells us how well heat travels through a material. 4. The lower the U-value, the better it is at insulating.

Types of Energy • • • K H L G C S E E N

Types of Energy • • • Kinetic (movement energy) Heat (thermal energy) Light Gravitational potential Chemical potential Sound Electrical Elastic potential Nuclear

Energy Efficiency Wasted Input Useful

Energy Efficiency Wasted Input Useful

Sankey Diagram The thickness of each arrow is drawn to scale to show the amount of energy. Conservation of energy: total energy before = total energy after

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.

Example Efficiency = 75 x 100 = 15% 500

Electricity Generation 1. Non-renewable energy sources: 2. Renewable energy sources:

Electricity Generation 1. Non-renewable energy sources: coal, oil, gas and nuclear 2. Renewable energy sources: solar, HEP, wave, tidal, geothermal, biogas, wind

4 5 3 2 1 1. 2. 3. 4. 5. 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

National Grid 1. Step-up transformers increase …………. This reduces ………………. , and so reduces ………………. lost as ………. 2. Step-down transformers reduce …………………. . so that the power supply is safe to use.

National Grid 1. Step-up transformers increase voltage. This reduces current, and so reduces energy lost as heat. 2. Step-down transformers reduce voltage so that the power supply is safe to use.

Non-Renewable Energy source Coal Oil Gas Nuclear power Advantages Disadvantages

Non-Renewable Energy source Coal Advantages Disadvantages Relatively cheap to mine, Non-renewable, ready made fuels burning produces CO 2 Oil Short start-up time, ready made fuels Gas Slightly cleaner fuel than oil Non-renewable, and gas and is a ready made burning produces CO 2 fuel Nuclear power Produces lots of energy, does not produce CO 2 Non-renewable, burning produces CO 2 Non-renewable, produces dangerous nuclear waste

Renewable Energy source Wind Hydroelectric Solar Geothermal Advantages Disadvantages

Renewable Energy source Advantages Disadvantages Wind Renewable, no fuel costs No wind sometimes, noisy Hydroelectric Renewable, no fuel costs Can flood areas, disrupts habitats Solar Renewable, no fuel costs No sun at night, some countries don’t get enough sun in the day, panels are expensive Geothermal Renewable, no fuel costs Only available in volcanic regions,

Key Terms 1. Start-up time = 2. Base load = 3. Decommission = 4. Carbon capture and storage =

Key Terms 1. Start-up time = the time it takes to generate electricity from the moment the power station is started 2. Base load = the minimum amount of electricity needed all the time 3. Decommission = the process of dismantling a nuclear power station safely 4. Carbon capture and storage = technology that removes carbon dioxide emissions from other gases and prevents it from being released into the environment

Cost of electricity E=P×t Units: E - energy transferred in ………. . ; P - power in …………; T - time in ………. When calculating cost, power must be measured in …………. . To convert from W to k. W you must divide by 1, 000. E. g. 2, 000 W = 2, 000 ÷ 1, 000 = 2 k. W. total cost = number of units × cost per unit total cost = power (k. W) × time (h) × cost per unit

Cost of electricity E=P×t Units: E - energy transferred in k. Wh; P - power in k. W; T - time in h. When calculating cost, power must be measured in k. Wh. To convert from W to k. W you must divide by 1, 000. E. g. 2, 000 W = 2, 000 ÷ 1, 000 = 2 k. W. total cost = number of units × cost per unit total cost = power (k. W) × time (h) × cost per unit

Waves 1. Waves are …………. that transfer …………… from place to place without matter being transferred. 2. Some waves must travel through a …………………. (medium). 3. In transverse waves, the oscillations (vibrations) are at ……………. . ………………. . to the direction of travel and energy transfer. Eg. : electromagnetic waves 4. In longitudinal waves, the oscillations are along the …………………as the direction of travel and energy transfer. Eg. : sound and mechanical waves

Waves 1. Waves are vibrations that transfer energy from place to place without matter being transferred. 2. Some waves must travel through a substance (medium). 3. In transverse waves, the oscillations (vibrations) are at right angles to the direction of travel and energy transfer. Examples: electromagnetic waves 4. In longitudinal waves, the oscillations are along the same direction as the direction of travel and energy transfer. Examples: sound and mechanical waves

Key Features

Characteristics of Waves • All waves undergo reflection, refraction and diffraction.

Reflection 1. The angle of …………………. equals the angle of ………… 2. Waves are reflected uniformly from ………… surfaces. 3. Rough surfaces …………… 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.

Reflection 1. The angle of incidence equals the angle of reflection 2. Waves are reflected uniformly from smooth surfaces. 3. 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 1. Waves change …………… when they pass through substances with different …………. 2. This causes them to change ………… and this effect is called refraction. 3. If waves cross a boundary at an angle of 90° (the ……………. . ) no refraction occurs.

Refraction 1. Waves change speed when they pass through substances with different densities. 2. This causes them to change direction and this effect is called refraction. 3. If waves cross a boundary at an angle of 90° (the normal) no refraction occurs.

Diffraction 1. When waves meet a ……… in a barrier, they carry on through the gap and ……………. ……… 2. How much they spread out depends on how the …………. of the gap compares to the wavelength………………. of the waves. 3. Gap same size as wavelength = 4. Gap similar size to wavelength = 5. Gap larger than wavelength =

Diffraction 1. When waves meet a gap in a barrier, they carry on through the gap and spread out. 2. How much they spread out depends on how the width of the gap compares to the wavelength of the waves. 3. Gap same size as wavelength = no diffraction 4. Gap similar size to wavelength = lots of spreading out 5. Gap larger than wavelength = little spreading out

Sound 1. Sound waves are …………………. waves 2. Echoes are …………. of sound waves 3. Sound cannot travel in a ……………… 4. …………. . = loudness 5. ………… = pitch 6. The normal range of human hearing is between about 20 Hz and 20 k. Hz. The range becomes less as we get older. 7. Sounds with frequencies above about 20 k. Hz are called ultrasound.

Sound 1. Sound waves are longitudinal waves 2. Echoes are reflections of sound waves 3. Sound cannot travel in a vacuum 4. Amplitude = loudness 5. Frequency = pitch 6. The normal range of human hearing is between about 20 Hz and 20 k. Hz. The range becomes less as we get older. 7. Sounds with frequencies above about 20 k. Hz are called ultrasound.

Electromagnetic Spectrum

Electromagnetic Spectrum Radiowaves • …. . and …………. ; TVs use higher frequencies than radios • ………………. . allows radio signals to be received behind hills and repeater stations are used to improve reception Microwaves • ……………. . calls • Microwave transmitters and receivers on buildings and masts communicate with the mobile telephones in their range.

Electromagnetic Spectrum Radiowaves • 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 Microwaves • Mobile phone calls • Microwave transmitters and receivers on buildings and masts communicate with the mobile telephones in their range.

Electromagnetic Spectrum Visible Light • Visible light helps us to communicate via sight • Cameras and video recorders use visible light • Very bright light damages our eyes Infrared • Used in toasters, heaters and grills and can cause burns • Used in burglar alarms, remote controls and security alarms

Doppler Effect When a source (e. g. galaxy) moves ……………… an observer, the observed ………………. . and the frequency ………………. . When a source (e. g. galaxy) moves …………. . an observer, the observed ……………… and the frequency …………………. . .

Doppler Effect 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.

Red Shift and Big Bang 1. Red Shift = …………………. . in the ……………. of electromagnetic waves emitted by a star of galaxy due to its motion ………… from us. Further away = ……………… moving and bigger observed increase in wavelength. 2. Galaxies move away from us wave length increases suggests at one point in time the universe was all in one place. 3. The Big Bang Theory = the universe was created in a massive ………………. . from a very small point and is still ……………. . . 4. Evidence for the Big Bang Theory: ……………; Red Shift

Red Shift and Big Bang 1. Red Shift = Further away = faster moving and bigger observed increase in wavelength. 2. Galaxies move away from us wave length increases suggests at one point in time the universe was all in one place. 3. The Big Bang Theory = the universe was created in a massive explosion from a very small point and is still expanding. 4. Evidence for the Big Bang Theory: CMBR; Red Shift