Physics

• Chemical energy: food, fuels, chemicals, batteries, etc.
• Kinetic: moving objects
• Gravitational potential energy: The energy stored in an object due to its position on the ground.
• Elastic potential energy: stretchy objects
• Thermal energy: hot objects
• Closed system: a system where no energy transfer takes place out of or into stores of the system
• What is the energy store for when an elastic stretches?

  Elastic potential energy.
• Work done?


  force applied X distance
• Power= Work done / time taken
• Weight?

  mass X gravitational field strength
• Change in objects GPE is weight X what?

  change in height
• Change in GPE energy store is mass x gravitational field strength x what?

  change In height
• Kinetic energy is mass x speed x what?

  1/2
• Elastic potential energy is 1/2 x extension x what?


  spring constant
• 1 kg object is equivalent to what?

  10N
• Efficiency is useful output energy transferred by the devise divided by what?

  total input energy supplied to the device
• Input Energy is USEFULL Output Energy + what?

  wasted Energy
• Light bulbs useful energy is light emitted from it test of the energy is wasted as what?

  heat
• power wasted is total power in - what?

  useful power out
• oil, gas and coal are types of what?

  energy demands
• what is an example of wind power?

  wind turbines
• how do wave power generators work?

  waves move them up and down, the motion creates electricity
• how is hydroelectric energy generated?


  rainwater collected from reservoirs
• tidal power traps what?

  water from each high tide
• solar power uses what?

  radiation from the sun
• geothermal energy uses what?


  energy released by radioactive substances in the earth
• what are fossil fuel problems?


  greenhouse gases, global warming, non-renewable.
• supply of energy is higher when?

  in winter