Tiêu đề 4.Energy, work and power.pdf ✅

Topic 4 – Energy, work and power Page | 3 IGCSE Physics 0625 Paper 2 Pastpapers-2020 www.HakimAbbas.site 5 5A car of mass 800 kg travels over a hill of height h. By travelling to the top of the hill, the car gains 40 000 J of gravitational potential energy. The gravitational field strength g is 10 N / kg. What is the height h of the hill? A 5.0 m B 20 m C 50 m D 500 m 6 6The box contains the names of eight different energy resources. natural gas geothermal solar waves hydroelectric oil wind coal How many of these energy resources are renewable? A 3 B 4 C 5 D 6 7 7A lamp has a power input of 5.0 W. It wastes 1.0 W of power heating the surroundings. What is the efficiency of the lamp? A 20% B 50% C 80% D 120% 8 8A skier walks from the bottom of a ski slope to the top and gains 10 000 J of gravitational potential energy. She skis down the slope. At the bottom of the slope, her kinetic energy is 2000 J. How much energy is dissipated in overcoming friction and air resistance as the skier moves down the slope? A 2000 J B 8000J C 10 000 J D 12 000 J
Topic 4 – Energy, work and power Page | 4 IGCSE Physics 0625 Paper 2 Pastpapers-2020 www.HakimAbbas.site 9 9A coal-fired power station generates electricity. Coal is burnt and the energy released is used to boil water. The steam from the water makes the generator move and this produces electricity. Which words are used to describe the energy stored in the coal and the energy of the moving generator? coal generator A chemical hydroelectric B chemical kinetic C geothermal hydroelectric D geothermal kinetic 10 10Four different children run up the same set of stairs. For which child is the useful power to climb the stairs the greatest? mass of child / kg time taken / s A 40 15 B 50 25 C 60 25 D 70 15 11 11What needs to be known to calculate the work done by a force acting on an object?