P1

• What are the eight types of energy stores?

  Kinetic, gravitational potential, elastic potential, electrostatic, thermal, chemical, magnetic, nuclear
• What are the four types of energy transfer?

  Mechanical, electrical, heating, radiation
• What does the equation "Work done = energy transferred" imply?

  It indicates that the work done on an object results in an equivalent transfer of energy.
• What is a system in the context of energy transfers?

  • A single object or a group of objects.
  • Energy can be transferred, stored, or dissipated within the system.
• What is the formula for kinetic energy?

  E = \frac{1}{2}mv^2
• What is the formula for gravitational potential energy?

  E = mgh
• What does the conservation of energy principle state?

  Energy can be transferred, stored, or dissipated but cannot be created or destroyed.
• What is specific heat capacity?

  It is the amount of energy needed to raise the temperature of 1 kg of a substance by 1 °C.
• What is a closed system?

  A closed system is one where no energy or matter is transferred in or out, resulting in no overall change in total energy.
• What is power in terms of energy transfer?

  Power is the rate of energy transfer or the rate of doing work.
• How is power measured in watts?

  One watt (W) is equal to one joule of energy transferred per second.
• How does a 2 W motor compare to a 1 W motor in terms of energy transfer?

  A 2 W motor transfers more energy per second than a 1 W motor, allowing it to lift mass faster.
• What is the efficiency equation?

  Efficiency = \frac{\text{Useful output energy transfer}}{\text{Total input energy transfer}} \times 100
• Why can no device be 100% efficient?

  Because some energy is always dissipated as waste energy, often as thermal energy.
• What are the two ways to decrease how quickly a building cools?

  1. Increase the thickness of its walls.
  2. Use materials with lower thermal conductivity.
• What is conduction in terms of energy transfer?

  Conduction is the process where vibrating particles transfer energy to neighboring particles.
• What is convection in terms of energy transfer?

  Convection is where energetic particles move from hotter to cooler regions.
• How does lubrication reduce unwanted energy transfers?

  Lubrication reduces frictional forces between moving parts, decreasing energy dissipation.
• How does thermal insulation work to reduce energy transfers?

  Thermal insulation reduces unwanted energy transfers by heating, keeping energy within the system.
• What are non-renewable energy resources?

  Non-renewable energy resources are those that will run out one day.
• What are renewable energy resources?

  Renewable energy resources are those that will never run out.
• Name three fossil fuels.

  Coal, oil, natural gas
• What are the environmental impacts of burning fossil fuels?

  It releases CO₂, contributing to global warming, and sulfur dioxide, causing acid rain.
• What is the process of nuclear power generation?

  Nuclear fuel undergoes fission in nuclear reactors, generating electricity.
• What type of energy is solar power classified as?

  Renewable
• What are the advantages of wind power?

  Wind power produces no pollution when in use and is renewable.
• What do solar cells do?

  Generate electricity directly from sunlight
• What is a key environmental benefit of solar power?

  Produces no pollution when in use
• What are the disadvantages of wind power?

  Wind turbines can be noisy and spoil the view, and they are unreliable when wind conditions are not favorable.
• Why is solar power considered reliable in sunny countries?

  Because it is available during the daytime
• What do solar water heaters do?

  Use the sun to heat water
• What type of energy is geothermal power classified as?

  Renewable
• How is geothermal energy generated?

  From thermal energy stores of underground hot rocks
• What is a key environmental benefit of geothermal power?

  Does very little environmental damage
• What is hydro-electric power classified as?

  Renewable
• How does hydro-electric power generate electricity?

  Water is allowed out through turbines
• What is a negative environmental impact of hydro-electric power?

  Rotting plants release methane and CO₂
• Why is hydro-electric power considered reliable?

  Because it can generate electricity consistently, except in times of drought
• What type of energy is wave power classified as?

  Renewable
• How does wave power generate electricity?

  Waves move turbines up and down, forcing air through them