Temperature and Heat Transfer

1. Temperature and Heat Transfer Food and Cooking Unit Mrs. Caldwell’s Class

2. Temperature • Temperature is the measure of the kinetic energy of all particles in an object. • Remember that kinetic energy is the energy of motion and that all atoms are constantly in motion.

3. Examples of Temperature • If a liquid has a high temperature, the particles in the liquid are moving fast and have high average kinetic energy. • If a liquid has a low temperature the particles in the liquid are moving more slowly and have a low average kinetic energy. Low Average Kinetic Energy = Low Temperature High Average Kinetic Energy = High Temperature

4. Measuring Temperature • Temperature is measured in degrees. • The temperature scale used in science is the Celsius scale. • Water freezes at 0 degrees Celsius. • Water boils at 100 degrees Celsius. • A thermometer is used to measure temperature.

5. Heat – the flow of energy from an object at a warmer temperature to an object at a cooler temperature.

6. The Transfer of Heat Energy • Conduction – the process that moves energy from one object to another when they are touching physically. • Conductors – materials that transfer energy easily. • Example: Metals • Insulators – poor conductors. • Example: Foam Cup

7. The Transfer of Heat Energy • Convection – the process that transfers energy by the movement of large numbers of particle in the same direction within a liquid or a gas. • Example: warm and cold air in the atmosphere.

8. The Transfer of Heat Energy • Radiation – energy that ravels as electromagnetic waves, which include visible light, microwaves and infrared light. • Example: Microwave Oven

9. Questions • What is temperature? • What happens when a liquid is hot? Cold? • How is heat transfer demonstrated when you cook? • Will cold or hot water boil first? • What are the three ways that heat energy is transferred? • Name one example of a conductor and one example of an insulator.