Physics

• What does the law of conservation of energy state?

  Energy cannot be created or destroyed
• How can energy be transferred between stores?

  Energy can be transferred in four ways
• What are the four ways energy can be transferred between stores?

  • Mechanically
  • Electrically
  • Heating by particles
  • By radiation
• How is energy transferred electrically?

  Energy (J) = Charge (C) x Voltage (V)
• What is the equation for work done in mechanical energy transfer?

  Work Done (J) = Force (N) x Distance (m)
• How does heating by particles transfer energy?

  Heat transfers from hotter to cooler objects
• What is the method of energy transfer by radiation?

  Energy is transferred by waves
• Is any energy transfer 100% efficient?

  No, some energy is always wasted
• What happens to energy stores during a process?

  Energy decreases in some stores and increases in others
• What happens to gravitational potential energy (GPE) when an object falls?

  GPE decreases and kinetic energy increases
• What happens to kinetic energy when an object hits the ground?

  Kinetic energy becomes zero upon impact
• What is the formula for calculating efficiency?

  Efficiency = Useful energy output / Total energy input
• How is efficiency calculated for electrical appliances?

  Efficiency = Useful power output / Total input power
• How is wasted energy calculated?

  Wasted energy = Total energy input - Useful energy output