Energy - P1

• What are the 8 energy stores

  magnetic

  kinetic

  heat (thermal)

  gravitational

  chemical

  elastic

  electrical

  nuclear
• Describe the energy transfers that occur as a ball falls to the ground

  Gravitational potential -> Kinetic
• Give the equation for finding the energy in an object’s kinetic energy store

  Ek = 0.5 x m x v^2
• If energy is transferred to an object‘s kinetic energy store, what happens to its speed?

  speed increases
• Give the equation for finding the energy in an object‘s gravitational potential energy store

  Ep = m x g x h
• What kind of energy store is energy transferred to when you compress a spring?

  Elastic potential energy
• What is the definition of specific heat capacity of a material?

  How much energy is needed to heat up 1kg of a material by a temperature of 1•C
• Give the equation that relates energy transferred and specific heat capacity

  ΔE = m x c x Δθ
• Describe an experiment to find the specific heat capacity of a material

  Heater heats a metal block. Balance used to measure mass of block. Joule meter used to measure amount of energy to block. Thermometer used to measure amount of energy to block. Use mass, temp. change and energy to calculate specific heat
• State the conservation of energy principle

  Energy is never created or destroyed. Only changed from one form to another
• Define power and give an equation to calculate power

  P = E / t

  it is the rate of which energy is transferred
• What are the units of power

  Watts (W)
• How can you reduce unwanted energy transfers in a machine with moving, touching components?

  Use lubricants (like oil)
• T or F?

  A high thermal conductivity means there is a high rate of energy transfer

  True
• Give four ways to prevent unwanted energy transfers in a home

  Cavity walls

  loft insulation

  double-glazed windows

  draught excluders
• T or F?

  Thicker walls make house cool down quicker

  False
• Give the equation that relates efficiency to power

  Efficiency = useful power output / total power in
• The 5 renewable energy resources

  Solar

  wind

  hydroelectric

  wave

  tidal
• The 4 non-renewable energy

  Coal

  oil

  gas

  nuclear
• What is the difference between renewable and non-renewable energy resources?

  Non-renewable will run out whereas renewable will not
• give 2 disadvantages of burning fossil fuels

  Burning fossil fuels releases carbon dioxide (causes global warming) and sulphur dioxide (acid rain)
• Give a disadvantage of wind power

  Isn’t always windy (unreliable)
• give a disadvantage of hydroelectric power

  Have to flood a valley