Energy

• What is chemical energy?

  Anything that gets used up, such as food, fuels, batteries
• What is the conversion of energy?

  Energy is never created or destroyed, it is only transferred between different energy stores and different objects
• What is a closed system?

  A closed system is where neither matter nor energy can enter or leave. The net change in the total energy of a closed system is always zero
• What is gravitational potential energy?

  potential energy related to an object's height
• What is thermal energy?

  Heat energy, often wasted energy
• What is kinetic energy?

  energy of movement, depends on mass and speed
• What is elastic potential energy?

  the potential energy of an object that is stretched or compressed
• What is electrostatic energy due to?

  Due to electric charge
• What is Nuclear energy linked to?

  nuclear fusion/fission
• What is magnetic energy due to?

  due to magnetic field
• In what ways can energy be transferred?


  Mechanically, electrically, by heating, by waves/radiation
• What are the reasons for dissipation?


  due to friction, due to air resistance and due to electrical resistance
• How can dissipation be prevented?

  -friction: use a lubricant

  -air resistance: streamline the object (make it aerodynamic)

  -electrical resistance: use better conductors
• What does energy mean?

  The ability to do work, measured in joules (J)
• What does efficiency mean?

  Not wasting lots of energy
• What is work done measured in?

  Joules (J)
• What is work done?

  Another way of saying energy transferred
• What is power? What is it measured in?

  The rate of energy transfer. A higher power rating means more energy transferred so the appliance is more expensive to run. Measured in Watts (W)
• What does the amount of energy needed to heat a material depend on?

  Material, mass, how much it is being increased by
• What is specific heat capacity? What is it measured in?

  Specific heat capacity is the amount of energy needed for 1Kg of a substance to raise its temperature by 1°C. Physical property of a material. Measured in J/Kg°C.
• What is a non-renewable resource?

  A finite resource that is being used up faster than it is being created, therefore will run out eventually.
• Give examples of non-renewable energy resources

  Coal, Oil, Gas ( Fossil Fuels)

  Uranium, Plutonium (Nuclear Power)
• Give examples of renewable energy sources

  Solar Power

  Wind Power

  Hydroelectric Power- dams

  Geothermal- heat from centre of the earth

  Biofuels- burning organic matter

  Waves

  Tidal- sea level going up and down
• Give advantages of non renewable energy

  -Very high power output

  -Portable and versatile (fossil fuels)

  -Reliable

  -No Co2 Emissions (Nuclear)
• Give disadvantages of non renewable energy

  -Co2 emissions (fossil) and other pollutants

  -Finite resources

  -Radioactive waste (nuclear)

  -Long time to start and dismantle (nuclear)
• Give advantages of renewable energy

  -No Co2 emissions
• Give disadvantages of renewable energy

  -Unreliable
• How do you calculate percentage change?


  Percentage Change = Difference between numbers/Initial number x 100