GCSE Physics (AQA)

346 videos | 23 hours

Energy Energy changes in a system, and the ways energy is stored before and after such changes

Systems

2:48 Energy, Systems and How to Transfer Energy
Spec 4.1.1.1
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  • A system is an object or a group of objects.
  • Examples of systems:
  • Throwing a ball in the air: includes the ball, hand, and muscles.
  • Boiling water: includes the kettle, water, heater, and electrical components.
  • Plane taking off: includes the plane, engine, and fuel.
  • Changes in a system involve changes in energy storage.
  • Energy changes when throwing a ball:
  • Ball gains gravitational potential energy (GPE).
  • Energy sourced from food provides chemical energy to muscles.
  • Hand transfers kinetic energy to the ball.
  • Kinetic energy converts to GPE as the ball gains height.
  • GPE converts back to kinetic energy when the ball falls.
  • Energy changes in a kettle:
  • Electrical energy converts to thermal energy for heating water.
  • Electrical energy from the grid powers the heater.
  • Heat flows from the heater to the water.
  • Energy changes in a plane taking off:
  • Fuel provides chemical energy, converting to mechanical energy.
  • Propellers spin, moving the plane forward and gaining kinetic energy (KE).
  • Plane gains speed and GPE as it gains height.
  • Fuel prevents loss of kinetic energy.

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