Energy SAT Questions 5-7 1. Luke investigated the heating of water. He predicted that the rise in temperature would depend on the volume of water. The diagram shows the apparatus he used. thermometer stiring rod 3 100 cm beaker water candle block Luke recorded his results in a table as shown below. beaker volume of water, in cm3 temperature at start, in °C temperature after 2 minutes, in °C A 25 18 30 B 50 18 24 C 75 18 22 (a) Why did Luke need to know the temperature of the water at the beginning and at the end of the experiment? ..................................................................................................................... ..................................................................................................................... 1 mark (b) Did Luke’s results support his prediction? Explain your answer. ..................................................................................................................... ..................................................................................................................... greenwich bulk LEA 1 1 mark greenwich bulk LEA 2 (c) Luke stirred the water during the experiment. How did this make his results more reliable? ..................................................................................................................... ..................................................................................................................... 1 mark (d) Which of the following statements about the energy transferred to the beakers is correct? Tick the correct box. Much more energy went into beaker ‘A’ because its temperature increased the most. The same amount of energy went into all three beakers. Beaker ‘C’ received the most energy because there was more water to heat. 1 mark (e) After a time, all three beakers cooled down to room temperature. What happened to the thermal energy in the beakers as they cooled down? ..................................................................................................................... ..................................................................................................................... 1 mark Maximum 5 marks 2. (a) Jacquie has a mobile phone. Energy is stored in the battery of the phone. The drawing shows the battery being charged. greenwich bulk LEA 3 (i) Which energy transfer takes place in the battery as it is being charged? Tick the correct box. chemical to sound sound to thermal electrical to chemical thermal to electrical 1 mark (ii) When the battery is fully charged, Jacquie unplugs the phone. Which energy transfers take place when the mobile phone rings? Tick the correct box. chemical to electrical to sound electrical to chemical to sound kinetic to electrical to sound thermal to electrical to sound 1 mark (b) Jacquie can change the ring-tone of her phone. The diagrams below show the patterns made by four sound waves on an oscilloscope screen. They are all drawn to the same scale. greenwich bulk LEA 4 Write the letter of the sound wave that matches each of the descriptions below. (i) a loud sound with a low pitch ................. (ii) a quiet sound with a high pitch ................. (iii) a loud sound with a high pitch ................. 3 marks Maximum 5 marks 3. Fossil fuels are used to generate electricity, but over half of the world’s population uses biomass as a fuel. (a) What is ‘biomass’, which is used as a fuel? .......................................................................................................................... .......................................................................................................................... 1 mark (b) Biomass and fossil fuels are both energy resources. What is the original source of this energy? .......................................................................................................................... .......................................................................................................................... 1 mark (c) Give the names of three fossil fuels which are often burned to generate electricity. 1. ........................................................ 2. ........................................................ 3. ........................................................ 1 mark (d) Fossil fuels are often described as non-renewable energy resources. Explain why they are called ‘non-renewable’. .......................................................................................................................... .......................................................................................................................... 1 mark greenwich bulk LEA 5 (e) There are advantages and disadvantages of burning different fuels. (i) Give one advantage of using biomass rather than fossil fuel as an energy resource. ................................................................................................................. ................................................................................................................. 1 mark (ii) Give one advantage of using fossil fuel rather than biomass as an energy resource. ................................................................................................................. ................................................................................................................. 1 mark (iii) Give one disadvantage of using both fossil fuel and biomass. ................................................................................................................. ................................................................................................................. 1 mark Maximum 7 marks 4. The drawing below shows a solar panel fixed to the roof of a house in Britain. greenwich bulk LEA 6 (a) Daniel measured the energy output from this solar panel during one day in June. The graph below shows his results. 1.2 1.0 0.8 energy output 0.6 (kJ/s) 0.4 0.2 0 2am 4am 6am 8am 10am noon 2pm 4pm 6pm 8pm 10pm 12pm time of day (i) Why does the energy output from the solar panel vary during the day? ............................................................................................................. ............................................................................................................. 1 mark (ii) Daniel used the solar panel to run a motor. The motor needs 0.7 kJ/s to run at full speed. Use the graph to find out how long Daniel’s motor would run at full speed. ............... hours 1 mark greenwich bulk LEA 7 (b) Daniel measured the energy output from a different solar panel. This type of solar panel turns so that it always faces the Sun. The graph below shows the energy output for this panel during one day in midsummer. 1.2 1.0 0.8 energy output 0.6 (kJ/s) 0.4 0.2 0 2am 4am 6am 8am 10am noon 2pm 4pm 6pm 8pm 10pm 12pm time of day (i) On the graph above draw another curve to show how the energy output for this solar panel might vary on a day in mid-winter. 2 marks (ii) Between 7am and 7pm the solar panel turns through an angle of 180°. Calculate the angle the solar panel turns through each hour. ............................................................................................................. .................................................................................................degrees 1 mark maximum 5 marks greenwich bulk LEA 8 5. Sam turns his bicycle upside down and turns the pedals fast so that the back wheel spins. Sam holds a piece of card close to the back wheel. The spokes hit the piece of card and Sam hears a ‘musical’ tone. (a) Explain why the card produces a ‘musical’ tone. ......................................................................................................................... ......................................................................................................................... 1 mark (b) When the spokes hit the piece of card, the wheel slows down (i) Describe the energy change which occurs as the wheel slows down. ................................................................................................................. ................................................................................................................. 1 mark (ii) Describe and explain what will happen to the pitch of the ‘musical’ tone as the wheel slows down. ................................................................................................................. ................................................................................................................. 2 marks Maximum 4 marks greenwich bulk LEA 9
