1.7.3. Energy resources
A subsection of Physics, 5054, through 1. Motion, forces and energy
Listing 10 of 46 questions
shows a wind turbine. blades circular area The wind blows directly towards the turbine with a speed of 12 m / s. In one second, 60 000 kg of air passes through the circular area swept out by the blades. Calculate the kinetic energy of this mass of air. kinetic energy = A wind turbine releases no carbon dioxide into the atmosphere while generating electricity. Compared with a coal-fired power station, this is an advantage of using a wind turbine. State one reason why it is important to reduce the amount of carbon dioxide produced. Suggest one advantage of using a coal-fired power station compared with a wind turbine. A coal-fired power station releases 0.96 kg of carbon dioxide when it generates 1.0 kW h of electrical energy. Define the kilowatt-hour (kW h). Calculate the mass of carbon dioxide saved when the wind turbine has a power output of 2000 kW and operates for 12 hours. mass = Wind energy is a form of renewable energy. State the name of one other form of renewable energy.
5054_s22_qp_21
THEORY
2022
Paper 2, Variant 1
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Use One type of renewable energy source is shown in . Earth’s surface hot water and steam up cold water down cracks in hot rocks State the name of the renewable energy source shown in . State what is meant by a renewable energy source. 1000 kg of cold water at a temperature of 20 °C is pumped down to the hot rocks. 100 kg of water returns as steam and 900 kg as hot water, both at a temperature of 100 °C. The specific heat capacity of water is 4200 J / (kg °C) and the specific latent heat of vaporisation of water is 2.3 × 106 J / kg. Calculate the energy needed to heat 1000 kg of water from 20 °C to 100 °C, energy = the energy needed to produce 100 kg of steam from water that is already at 100 °C. energy =
5054_w07_qp_2
THEORY
2007
Paper 2, Variant 0
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A large power station burns oil to heat water in a boiler. State the name of the form of energy stored in the oil before it is burnt. State and explain whether oil is a renewable or a non-renewable energy source. Describe one environmental issue caused by burning oil to generate electricity in a power station. State what is meant by efficiency. The efficiency of the power station is 0.38 (38%). Its electrical power output is 1.9 × 109 W. Calculate 1. the input power to the power station, input power = 2. the energy wasted in 2.0 hours. energy wasted =
5054_w16_qp_21
THEORY
2016
Paper 2, Variant 1
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Questions Discovered
46