1. Thermal Energy Chapter 6

2. Temperature • Matter is in constant random motion, and hot particles move faster than cold ones because hot particles have more kinetic energy • Temperature is the measure of the average kinetic energy of the particles of an object • Temperature is often measured in Celsius or Fahrenheit

4. Heat • Heat is thermal energy that flows from something from higher temperature to something at a lower temperature • Heat is a type of energy, so it is measured in Joules • When ice melts, the thermal energy from the warmer air transfers to the colder ice, making it melt

5. Specific Heat • The amount of heat needed to raise the temperature of 1 kg of a substance’s temperature 1 degree Celsius • The higher the specific heat, the more energy is needed to change the temperature of the substance • Water has a very high specific heat • Metal and sand have a very low specific heat

6. Water as a Coolant • Water has a very high specific heat, meaning it takes a lot of energy to break the bonds between the molecules and allow the temperature to rise • Because of this, water is used as a coolant • Think of a swimming pool vs the concrete around the pool

7. Calculating Heat Energy • Q= Heat Energy in Joules • ΔT= Change in Temp in degrees C • M= mass in kg • C= specific heat (constant) Q M C ΔT

8. Specific Heat Constants

9. Transferring Thermal Energy • Conduction- heat transfer by touching • Example: A metal spoon in hot coffee • Sitting in a chair and the chair gets warm • The best heat conductors are metals, silver, copper and aluminum are the best conductors of heat

10. Convection • Transfer of thermal energy in a fluid by the movement of fluids from a warmer place • Example: Heating up water in a bathtub by adding more hot water • Lava Lamp • Example: Weather patterns

11. Radiation • Earth gets heat from the sun, heat can only travel from the sun to the Earth by radiation, because conduction and convection both require matter • Radiation is the transfer of energy by electromagnetic rays • Often called radiant energy

12. The Electromagnetic Spectrum

13. Controlling Heat Flow • Putting on a coat or an oven mitt are both examples of trying to control the flow of heat • Many animals have adaptations that help them control the flow of heat • Penguins have a layer of blubber and thick, closely spaced feathers • Reptiles have scaly skin that helps to reflect sunlight

14. Insulators • A material in which heat flows slowly • Gases are usually better insulators than solids are liquids • Buildings are insulated to keep warm air in the building during the winter and cool air in the summer • Fleece jackets trap warm air pockets close to your body