P2: energy transfer by heating

• Conduction


  The transfer of heat energy across a surface
• Hot particles


  • Vibrate a lot when heated
  • Cooler particles vibrate less and have less thermal and kinetic energy
• Conduction


  1. Fast-moving particles collide with not as fast-moving particles sitting next to them

  2. This causes the heat energy to be transferred along a solid
• Good conductors of heat

  Frying pans, to warm up food
• Insulators


  Keep heat inside a house
• Double glazing


  • Better insulator than single glazing
  • Has air gaps, air is a poor conductor of heat
• Loft insulation


  • Has air gaps, similar to cotton wool, keeps heat in
• Cavity wall insulation


  • Insulating material blown between bricks, leaving an air gap
• Specific heat capacity


  The amount of energy required to heat one kilogram of an object by one degree Celsius
• Calculating specific heat capacity

  1. Measure starting temperature

  2. Measure energy transferred and temperature rise over time

  3. Plot graph of energy vs temperature rise

  4. Use formula to calculate specific heat capacity
• Easier to calculate specific heat capacity if mass of object is 1 kg