1. Engineer-in-Residence Program Heat John Hazel, P.Eng.

2. What is Heat ? Transfer of energy between things Measured in Joules, Watts or Calories Temperature is the average energy of things William Thompson (Lord Kelvin) James Joule

3. Heat Transfer

4. Heat in a Car Engine Fluid heated by engine Fluid heats core (conduction) Fan cools fluid (convection) Some fluid used to transfer heat to car heater

5. Specific Heat Capacity The amount of energy required to increase 1 kg of something by 1 degree

6. Specific Heat Capacity itemC (J/kg.K) ItemC (J/kg.K) Water4190Glass750 Flesh3500Stainless steel510 Wax2500Iron448 Wood (oak)2390Nickel439 Petroleum2140Copper385 Air1000Brass370 Aluminum900Gold130

7. What Makes the Best Pot Handle ?

8. Insulation

9. Effects of Heat on Materials When things get hot they expand since they have more energy New Volume = Old volume X Temperature change x Coefficient of Expansion ItemCoeff of exp Aluminum.000007 Steel3.6 Copper4.2

10. Protecting Bridges Some bridges can get several feet longer on a hot day If it has nowhere to go, it will buckle and crack due to thermal stresses

11. How Cold? The colder things are, the less energy they have Absolute zero is 0 K or -273.15 C Strange things happen to matter at absolute zero: superconductors superfluidity