Physics 1

1. Physics 1 Which key terms do I need to remember?

2. How to use this powerpoint • This powerpoint covers all the material in the P1 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 slideLook 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-schemesGood Luck!

3. States of Matter Solid Liquid Gas

4. States of Matter

5. Transfer of Energy

6. 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.

7. 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.

8. 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.

9. 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.

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

11. 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

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

13. 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

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

15. 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

16. 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 ………-………………………………

17. 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.

18. 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.

19. Specific Heat Capacity 1. Specific heat capacity of materials tells us how much energy is needed to increase the temperature of 1kg 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.

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

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

22. Energy Efficiency Wasted Input Useful

23. Energy Efficiency Wasted Input Useful

24. 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

25. 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.

26. Example Efficiency = 75 x 100 = 15% 500

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

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

29. 4 5 3 2 1 • 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

30. 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.

31. 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.

32. Non-Renewable Energy

33. Non-Renewable Energy

34. Renewable Energy

35. Renewable Energy

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

37. 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

38. 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 kW you must divide by 1,000. E.g. 2,000 W = 2,000 ÷ 1,000 = 2 kW. total cost = number of units × cost per unit total cost = power (kW) × time (h) × cost per unit

39. Cost of electricity E = P × t Units: E - energy transferred in kWh; P - power in kW; T - time in h. When calculating cost, power must be 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. total cost = number of units × cost per unit total cost = power (kW) × time (h) × cost per unit

40. 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

41. 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

42. Key Features

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

44. 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.

45. 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.

46. 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.

47. 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.

48. 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 =

49. 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

50. 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 kHz. The range becomes less as we get older. 7. Sounds with frequencies above about 20 kHz are called ultrasound.