Physics

• Temperature (A physical quantity, that can be measured, that determines the rate at which heat flows from a 'hot' body to a 'cold' body)


  • Directly proportional to the average kinetic energy
  • Measured in Kelvin (K)
  • Based on the absolute zero point, which is -273°C = 0K
  • Convert Celsius to kelvin -> 483K - 273 = 210 degrees Celsius
• Heat (Q)


  • Form of energy transfer
  • Spontaneous flow of energy from one object to another caused by temperature difference.
• Thermal equilibrium

  When the temperature between 2 objects is the same, heat flows back and forth at the same rate, keeping the temperature constant.
• Work done ( Force x Distance)


  Force = Pressure x area

  ->Pressure x area x height (distance) = Work done

  ->Area x height = volume -> Pressure x volume = Work done

  
  

  Compression = Work done ON the gas

  Expansion = Work done BY the gas onto the surface of container
• Charles Law

  The volume of a fixed amount of gas, that is kept at a constant pressure, is directly proportional to its temperature.

  
  

  ->As you increase the temperature, particles move around quicker and collide more often with the surface causing the volume to increase.

  
• Power and Efficiency

  Power (Watts) = Energy transfer (J) ÷ Time (s)

  Efficiency is how much of the energy that you use ends up in the form you are trying to transfer.

  -> Efficiency = (Useful energy output ÷ Total input) x 100

  -> Power
• ∆U = Q + W (Compression, Work done ON)

  
  

  ∆U = Q + W (Expanding, Work done BY)