Transfer of Energy What does Transfer of Energy

Transfer of Energy

What does “Transfer of Energy” mean? How heat (energy) moves.

Heat moves from hot Source cold Sink HIGH LOW TEMPERATURE FLOW of HEAT

• Heat will always flow from a source sink ______ to a ____ until equilibrium is reached. Sink Source • Heat (energy) is transferred by conduction _____, convection or _____, radiation _____.

Methods of Heat Transfer 1. CONDUCTION - Direct transfer from atom to atom caused by molecules vibrating and colliding (touching). *most effective in solids, especially metals* metals

Conduction Example Warmer End Cooler End

2. Convection: Transfer of ____ heat by cyclic movement of fluid. *Based on differing densities. * Ex: liquid & gas.

Convection Current Example Convection Current 2. On reaching the surface the water ______ cools in contact with the air. 3. As the water ______ cools it becomes _____ more dense and ________ sinks. A cycle develops, we call this a _____ convection current or cell. ____ heat 4. 1. As the water is ______ heated it becomes _____ less dense and _______ rises.

3. Radiation: Transfer of heat via electromagnetic waves. Can occur in solid, liquid, gas, and space.

Conduction Convection Radiation

Exercise #3 - Transfer of Energy • Label each of the pictures with the primary form of energy transfer that is taking place. • *Remember* Conduction, Convection, Radiation. • Please work quietly!

1. Radiation!

2. Convection!

3. Conduction!

4. Convection!

5. Conduction!

6. Radiation!

7. Conduction!