physics paper 1

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Created by
marko janbergs

Cards (56)

  • Energy Stores

    1) Elastic potential
    2) Gravitational potential
    3) Thermal
    4) Electrostatic
    5) Nuclear
    6) Chemical
    7) Kinetic
    8) Magnetic
    9) Light
    10) Sound
  • How is energy transferred?

    1) Mechanically - force doing work
    2) Electrically - work done by moving charges
    3) Heating/Radiation - light, sound
  • How can work be done?
    When a current flows or by a force moving an object
  • What happens when an object falls and there's no air resistance?
    Energy lost from the g.p.e store = energy gained in the kinetic energy store
  • What does air resistance do when acting against falling objects?
    It causes some energy to be transferred to other energy stores e.g. the thermal energy stores of the object and the surroundings
  • What is SHC?
    The amount of energy needed to raise the temperature of 1kg of a substance by 1°C
  • What is the conservation of energy principle?
    Energy can be transferred usefully, or stored or dissipated (wasted energy), but can never be created or destroyed
  • What is power?
    The rate of energy transfer, or the rate of doing work
  • What is 1W equal to?
    1J of energy transferred per second
  • What is conduction?
    The process where vibrating particles transfer energy to neighbouring particles
    Energy is transferred to thermal stores of the object - this energy is shared across the kinetic energy stores
  • What is thermal conductivity?
    A measure of how quickly energy is transferred through a material via conduction
  • What is convection?
    Where energetic particles move away from hotter to cooler regions
    Energy is transferred to the thermal energy stores of the object and is shared across the kinetic stores
  • What do radiators create?
    Convection currents
  • Convection currents - process
    1) Energy is transferred from the radiator to the nearby air particles by conduction
    2) The air by the radiator becomes warmer and less dense as the particles move quicker
    3) The warm air rises and displaces the cooler air, which is then heated by the radiator
    4) The previously heated air transfers energy to the surroundings - the air cools, becomes denser and sinks
  • What does lubrication do?
    Reduce frictional forces
  • What does insulation do?
    Reduce the rate of energy transfer by heating
  • Thermal insulation techniques
    1) Cavity walls - made up of an inner and outer wall with an air gap in the middle - the air gap reduces the amount of energy transferred by conduction through the walls
    2) Cavity wall insulators - the air gap is filled with foam also reduces energy transfer by convection in the wall cavity
    3) Loft insulation - reduces convection currents being created in lofts
    4) Double-glazed windows - air gap between two sheets of glass that prevent energy transfer by conduction through the windows
    5) Draught excluders - reduce energy transfers by convection around doors and windows
  • How do you improve efficiency?
    1) Lubrication
    2) Insulation
    3) Making objects more streamlined
  • Is any device 100% efficienct?
    No
  • Where is wasted energy usually transferred?
    Thermal energy stores
  • How do thick walls prevent energy losses through heating?
    They're made from a material with a low thermal conductivity - the thicker the walls, the lower the thermal conductivity, the slower the rate of energy transfer
  • What objects are usually 100% efficient?
    Electric heaters - all the energy in the electrostatic energy stores is transferred to useful thermal energy stores
  • Fossil fuels (coal, oil, natural gas)
    Non-renewable
    Cause acid rain
    Cause global warming
    Reliable currently - they are finite, so they will run out eventually
    Coal mining ruins the landscape
    Oil spillages cause serious environmental problems
  • Energy resources used for transport
    Petrol and diesel from oil - non-renewable
    Coal (steam trains) - non-renewable
    Bio-fuels - renewable
  • Energy resources used for heating
    Natural gas - non-renewable
    Coal - non-renewable
    Electric heaters - non-renewable
    Geothermal - renewable
    Solar water heaters - renewable
    Bio-fuels - renewable
  • Wind Power
    Renewable
    Doesn't cause global warming
    Doesn't cause acid rain
    No pollution
    No permanent damage to the landscape
    Free - initial costs are high
    Very noisy
    Spoil the view
    Not always reliable
  • Solar Power

    Renewable
    Doesn't cause acid rain
    Doesn't cause global warming
    No pollution
    Free - solar panels are expensive though
    Not always reliable
  • Geothermal Power

    Renewable
    Doesn't cause acid rain
    Doesn't cause global warming
    Free
    Very little damage to the environment
    Not very reliable - can only happen in certain places and there aren't very many of them
  • Hydroelectric Power

    Renewable
    Reliable
    Doesn't cause acid rain
    Doesn't cause global warming
    No pollution
    Provides an immediate response to high demand
    Free - initial cost is high
    Big impact on environment and possible loss of habitat
  • Wave Power

    Renewable
    Doesn't cause acid rain
    Doesn't cause global warming
    Free - initial costs are high
    Not always reliable - waves die out when the wind drops
    Disturbs the seabed and habitats of marine wildlife
    Spoils the view
    Hazard to boats
  • Tidal Power

    Renewable
    Reliable
    Doesn't cause acid rain
    Doesn't cause global warming
    No pollution
    Free - initial costs are moderately high
    Spoils the view
    Alters the habitats of wildlife
  • Bio-fuels

    Renewable
    Reliable
    Doesn't cause acid rain
    Carbon neutral
    Free
    Can cause global warming
    Loss of natural habitat from destruction of forests
    Cannot respond to immediate energy demands
  • Nuclear Power (Uranium or Plutonium)

    Doesn't cause acid rain
    Doesn't cause global warming
    Reliable currently - finite
    Non-renewable
    High decommissioning costs
    Produces radioactive waste - no other pollution
    Nuclear waste is dangerous and hard to dispose of
  • Investigating Specific Heat Capacities - Method
    1) Measure the mass of a block with two holes in it, then wrap it in an insulating layer (e.g. newspaper) to reduce the energy transferred from the block to the surroundings. Insert the thermometer into one hole and the heater into another
    2) Measure the initial temperature of the block & set the potential difference of the power supply to be 10V. Turn on the power supply & start a stopwatch
    3) When you turn on the power, the current in the circuit does work on the heater, transferring energy electrically from the power supply to the heater's thermal energy stores - this energy is then transferred to the material's thermal energy store by heating, causing its temperature to increase
    4) As the block heats up, take readings of the temperature and current every minute for 10 minutes - the current shouldn't change
    5) Turn off the power supply. Use the measurements of the current & the p.d. to calculate the power supplied to the heater, thus calculating how much energy has been transferred to the heater at the time of each temperature reading
    6) If you assume all the energy supplied to the heater has been transferred to the block, you can plot a graph of energy transferred to the thermal energy store of the block against temperature
  • Investigating the Effectiveness of Materials as Thermal Insulators - Method
    1) Boil water in a kettle. Pour some of the water into a sealable container to a safe level. Measure the mass of water in the container
    2) Use a thermometer to measure the initial temperature of the water
    3) Seal the container & leave it for 5 minutes. Measure this time using a stopwatch
    4) Remove the lid & measure the final temperature of the water
    5) Pour away the water & allow the container to cool to room temperature
    6) Repeat this experiment, but wrap the container in a different material once it has been sealed. Ensure the mass of water is the same and so is the initial temperature each time
  • What is a closed system?
    A system where neither matter nor energy can enter or leave
  • Why did electricity use in the 20th century increase?
    1) The population grew
    2) People began to use electricity for more & more things
  • Why did electricity use in the 21st century decrease?
    1) Appliances are becoming more efficient
    2) We're more careful with energy use in our homes
  • Why are we trying to increase our use of renewable energy resources?

    1) Burning fossil fuels is damaging to the environment
    2) Non-renewables will run out one day
    3) Pressure from other countries & the public has led to targets being set e.g the UK aims to use renewable resources to provide 15% of the total yearly energy by 2020
  • What has pressure from the public & other countries led to?
    Pressure being put on energy providers to build new power plants that use renewable resources to ensure that they don't lose business & money