P1

• Law of conservation of energy

  Never created or destroyed, only transferred between different forms and objects
• Forms of energy

  • Thermal or internal energy
  • Kinetic energy
  • Gravitational potential energy
  • Elastic potential energy
  • Chemical energy
  • Magnetic energy
  • Electrostatic energy
  • Nuclear energy
• Energy transfer


  1. Mechanical

  2. Electrical

  3. Heating

  4. Radiation (light or sound waves)
• System


  A group of objects or a single object.
• Open system


  Can exchange energy with the outside world
• Closed system


  Separate from the outside world, neither matter nor energy can enter or leave
• Work done


  Energy transferred
• Types of work done

  • Mechanical
  • Electrical
• In terms of energy, what happens when a moving object hits an obstacle?

  The Kinetic energy is transferred to heat and sound and the kinetic energy of the obstacle that was hit
• What happens in terms of energy when an object is accelerated by a constant force


  Work is done by a force on an object

  This work is converted to the objects kinetic energy store
• What happens in terms of energy when a vehicle is slowing down

  The kinetic energy of the vehicle decreases while energy is dissipated through heat and sound
• What happens in terms of energy when water is brought to the boil in an electric kettle

  Energy transfers from the electrical store of the mains power supply to the thermal store of the water
• What is the unit for kinetic energy


  Joules, J
• What is the unit for mass

  Kilograms, Kg
• What is the unit for speed

  Metres per second, m/s
• What is the unit for elastic potential energy


  Joules, J
• What is the unit for spring constant

  Newtons per metre, n/m
• What is the unit for extension

  Metres, m
• What is the unit for GPE 


  Joules, J
• What is the unit for gravitational field strength


  Newtons per kilogram, n/kg
• What is the unit for height

  Metres, m
• What is the definition of power

  The rate at which energy is transferred

  The rate at which work is done
• What is the unit for power

  Watts, W
• What is the unit for energy transferred 


  Joules, J
• What is the unit for time

  Seconds, S
• What is the unit for work done

  Joules, J
• What is an energy transfer of 1 joule per second equal to?

  1 watt