Paper 1 Topics

• System

  A group of connected (or related) objects we are studying
• Surroundings

  Everything else in the universe, other than the system we are studying
• Energy stores

  • Kinetic
  • Chemical
  • Thermal
  • Gravitational Potential (GPE)
  • Elastic Potential
  • Nuclear
  • Electrostatic
  • Magnetic
• Energy transfers

  • Mechanically
  • Electrically
  • By Heating
  • By radiation
• Energy transfer when a ball is thrown upwards

  Kinetic -> GPE
• Energy transfer when a ball hits a wall

  Kinetic -> Elastic & Thermal
• Energy transfer when a car brakes

  Kinetic -> Thermal
• Energy transfer when a kettle boils water

  Thermal (kettle) -> Thermal (water)
• Gravitational Potential Energy (GPE)

  mass (kg) x gravity (N/m) x Δheight (m)
• Kinetic Energy

  ½ x mass (kg) x velocity (m)^2
• Elastic Potential Energy


  ½ x spring constant (N/m) x extension (m)^2
• Energy cannot be created or destroyed, only transferred
• Dissipation

  Transfer of "wasted" energy, usually to the thermal store of the surroundings
• Friction causes objects to heat up and transfer energy from their thermal stores to the thermal stores of the surroundings</b>
• Conduction

  Heat transfer through direct contact between a hotter solid and a cooler solid
• Radiation

  Heat transfer from all hot objects as infrared radiation
• Thermal conductivity

  Measure of how quickly energy can transfer through a solid
• Materials with low thermal conductivity are useful for reducing energy dissipation by heating
• Energy efficiency

  Ratio of useful energy output to total energy input
• Specific heat capacity (c)

  Amount of joules needed to raise 1 kg of a material by 1 degree
• Investigating specific heat capacity

  Set up equipment, record temperature changes, calculate power and energy transferred, plot graph, calculate heat capacity
• Power

  Rate of energy transfer, measured in watts (W = J/s)
• Investigating thermal insulation

  Compare effectiveness of different materials, investigate effect of material thickness
• Independent variable (IV)

  Thickness of insulating material
• Control variables (CV)

  • Times that temperature is measured
  • Volume of water
  • Type of insulating material
• Independent variable (IV)

  Thickness of material
• Dependent variable (DV)

  Thermal insulation
• Non-renewable resources produce lots of energy and are very reliable, but tend to produce carbon dioxide which is a greenhouse gas
• Non-renewable resources

  • Nuclear
  • Fossil fuels: Coal, Oil, Gas
• Advantages of fossil fuels

  • Produce lots of energy
  • Very reliable
• Disadvantages of fossil fuels

  Produce carbon dioxide, a greenhouse gas
• Renewable resource

  One that is being (or can be) replenished as it is used
• Renewable resources

  • Wind
  • Tidal power
  • Solar
  • Hydro power
  • Bio-fuels
  • Waves
  • Geothermal
• Advantages of renewable energy

  Produce less energy and are often dependent on weather or time of day, but tend to not produce carbon dioxide which is a greenhouse gas
• Disadvantages of renewable energy

  Produce less energy, often dependent on weather or time of day, cannot predict the size of waves
• Countries are gradually shifting to renewables because of climate change and as renewable technology improves
• Current


  The rate of flow of charge, measured in amps
• Potential difference (voltage)

  The energy transferred per charge, measured in volts
• Difference between series and parallel circuits

  Series circuit has one loop with no junctions, parallel circuit has more than one loop with junctions
• Ammeters

  Measure current and must be connected in series