Velocity & Displacement (p4 – 6) Scalar quantities have a magnitude only. Vector quantities have a magnitude and direction. Scalars: Distance, Mass, Time, Energy. Vectors: Force, Velocity, Displacement, Acceleration (a) 10 m s-1 12 m s-1 30 s 48 s 360 m 7.5 m (a) 40 m 10m west 0.8 m s-1 0.2 m s-1 west (a) 0 m 8.89 m s-1 0 m s-1 (a) 700 m 500 m (053°) 0.78 m s-1 0.56 m s-1 (053°) (a) 18.3 m s-1 66 km h-1 13.0 m s-1 (140°) (a) 85.0 km h-1 46.1 km h-1 (283°) (a) 19.8 m s-1 15.4 m s-1 (260°) Acceleration (p7 – 8) (a) 2 m s-2 3 m s-2 9 m s-1 36 m s-1 4 s 4.2 s 2 m s-2 1.6 m s-2 22.5 s 9.9 m s-1 2.8 m s-1 -15 m s-2 0.1 m s-2 10 m s-2 Velocity-Time Graphs (p9 – 11) (a) Uniform acceleration Uniform deceleration Constant speed / zero acceleration Accelerates uniformly from rest. Stays at a constant speed. Decelerates uniformly until it has stopped. (a) 4 m s-2 8 m s-2 3 m s-2 -3 m s-2 (a) 56 m 12.6 m 43.5 m 118 m (a) A – ball is accelerating down towards ground. B – ball is bouncing on ground. C – ball is decelerating upwards. D – ball reaches highest point. E – ball is accelerating down towards ground. The ball is losing energy Weight (p12 – 13)
Work done is the energy transferred to an object. (a) 3000 J 155 J 2000 N 20 N 10 m 45 m 16 800 J 300 N 40 m 3 x 107 J 25 km 7890 N 6960 J 4.5 N Projectile Motion (p22 – 25) A projectile has vertical and horizontal motion at the same time. 27 m s-1 (a) 9.8 m 41.8 m (a) 25.6 m 2.24 m Monkey gets struck by arrow. It falls at the same rate as the arrow. Gun and bullet hit the ground at the same time. They fall at the same rate. (a) 2 s 6 m s-1 (a) 105 m 30 m s-1 (a) 1162.5 m 0 m 155 m s-1 Air resistance will slow the box. A projectile with a high enough horizontal velocity will fall with the curvature of the Earth, staying in orbit. Specific Heat Capacity (p26 – 27) 4180 J of heat energy is needed to change the temperature of 1 kg of water by 1 °C. (a) 47 000 J 112 750 J 4100 J kg-1 °C-1 270 J / J kg-1 °C-1 0.4 kg 5.5 kg 7.5 °C 4 °C 752 400 J 380 J kg-1 °C-1 2.5 °C 12 kg (a) 618 J kg-1 °C-1 The experimental value is larger. This is because not all heat energy is absorbed by the copper block. Specific Latent Heat (p28 - 30)
(a) The energy required to change 1 kg of a liquid in to a gas OR the energy given out by 1 kg of a gas turning in to a liquid. The energy required to change 1 kg of a solid in to a liquid OR the energy given out by 1 kg of a liquid turning in to a solid. (a) Melting Evaporating Freezing Condensing The stearic acid is changing state from solid to liquid. (a) 148 500 J 237 000 J 0.8 kg 1.3 kg 0.25 x 105 J kg-1 2.67 x 105 J kg-1 (a) 133 600 J 904 000 J (a) 904 000 J 133 600 J 0.9 kg (a) 3.77 x 105 J kg-1 Carbon Dioxide 389 160 J (a) 5.35 x 106 J kg-1 The experimental is larger. This is because some of the heat energy is being used to change the temperature of the water, rather than change its state. Space Exploration (p31 – 32) (a) 7.9 x 105 N The weight of the space shuttle decreases. This is because: is less mass due to fuel being used up. The shuttle is getting further away from the surface of the Earth. 1.35 x 106 N 2.51 x 1011 J Disagree. High specific heat capacity is required to stop the surface of the tiles increasing in temperature by too much. 753 °C Silica. It has a low density, a high specific heat capacity and a high melting point. Astronomers get a more detailed image of a planet than can be seen with the naked eye. Helps give a better idea of how the solar system was created. Telephones, television, GPS, etc. The Earth’s atmosphere can’t distort an image seen by the Hubble space telescope. Environment & Agriculture: Water purification, solar energy. Home: Memory foam, cordless vacuum cleaners. Industry: Lubricants, food safety. Medicine: Infrared ear thermometers, artificial limbs. Transport: Anti-icing systems, improved tyres.