P2 Knowledge Test Answers – Higher Tier 1. Rubbing / friction transfers electrons 2. repel 3. Balloon is negatively charged, it repels the electrons in the wall, it is attracted to the positive charge left in the wall. 4. The comb becomes negatively charged. It repels the negative charges in the paper meaning the positive charge is attracted to the comb which is why the paper is picked up. 5. As the clouds move past each other, charge builds up. Eventually the charge gets so large that it discharges through the atmosphere to Earth which is the lightening. 6. You have become charged. The electrons flow through you to the object to Earth. 7. Electrons can pass down the earthing cable when charge builds up so there isn’t a spark. Or the user doesn’t receive a shock. 8. Paint spraying, insecticide spraying 9. Charge can build up as the fuel flows along the pipe. This could potentially discharge as a spark to Earth setting the fuel on fire. 10. The flow of charge, the flow of electrons 11. direct current 12. In series, current, Amps 13. Increase 14. In parallel, voltage or p.d., volts 15. the energy transferred per unit charge/1 joule per coulomb 16. Reduces current because it is more difficult for the electrons to flow. 17. 2x10=20V 18. Resistance increases, current decreases. 19. Resistance decreases, current increases. 20. Heats up because there are collisions between electrons and the ions in the lattice. 21. Heating element in kettle, fire etc. 22. Quantities that have direction and size. Displacement, velocity, acceleration, force 23. A-B Constant Speed, B-C Stationary, C-D Accelerating, D-E Stationary, E-F Constant speed 24. 2m/s 25. A-B Accelerating, B-C Constant Speed, C-D Accelerating, D-E Constant Speed, E-F Decelerating, F-G Constant Speed, G-H Accelerating 26. C-D 27. 120m 28. 29. Equal and opposite 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46. 47. 48. 49. 50. 51. 52. 53. 54. 55. 56. 57. 58. 59. Stay at rest, or continue at a steady speed Accelerate or decelerate size of resultant force, mass of object At the same rate/speed 1 - increasing speed increases air resistance. 2 - Air resistance increases until it is equal to the weight of the falling object. 3 - When the two forces are balanced, acceleration is zero and terminal velocity reached. Thinking distance and breaking distance mass, speed, reaction time, state of breaks, state of tyres/friction between road and tyre, state of the road When a moving object collides with another object The momentum before the collision will be the same as the momentum after the collision. Increase the time taken for the object to stop thereby reducing the rate of change of momentum. Rate of doing work 1 joule per second Mass number = 14 = protons + neutrons, Atomic number = 6 = protons Loss of electrons alpha - helium nucleus/2p + 2n beta - high speed electron alpha, gamma 2 daughter nuclei and 2 neutrons and lots of energy released When some of the neutrons released by the fission of Uranium 235 are absorbed by other materials, meaning that only one of the two neutrons released goes on to be absorbed by another Uranium 235 nucleus, limiting the amount of energy released. Nuclear fission is the splitting of a large nucleus whereas fusion is the joining of small nuclei Control rods - absorb neutrons. Moderator - slows down neutrons. Heat energy transferred to a coolant which is usually water. This super-heated water is pumped to a heat exchanger where it is used to generate steam. The steam turns a turbine, which turns a generator which turns kinetic energy into electrical energy. They're radioactive the creation of large nuclei from smaller nuclei accompanied by the release of lots of energy Nuclear fusion It is need to overcome the electrostatic repulsion of protons. Because of the cost of maintaining high temperature and high pressures make it uneconomic. tissue damage, possible mutations in DNA Scientists became aware of the hazards and risks. Stored in concrete, steel and glass containers. No CO2 released Container could fall back to earth. Container could corrode and leak. 60. 61. 62. 63. 64. Becquerel (Bq) The time taken for half the undecayed nuclei to decay. The natural radiation level around us from Space, ground and rocks, radon gas. A detector counts the rate at which beta particles pass through the paper. If it is too high or too low the paper isn’t the right thickness. 65. Alpha particles from Americum-241 ionise the air to make ions and electrons. A current flows between two charged plates. When smoke gets in the air gaps, the current falls and sounds the alarm.