Transfer of Energy Energy Transfer Energy

Transfer of Energy

Energy Transfer • Energy is transferred from hotter object to colder object • Examples? – Cooking pasta – Making ice – Making popcorn – Roasting marshmallows

Conduction • Transfer of energy as heat between particles in direct contact • Example – Roasting marshmallow with wire – Stirring soup with a metal spoon

Conduction

Convection • Energy transfer through movement of fluids at different temperatures (fluids liquids and gases) • Examples – Camp fire – Boiling pot of water – Convection currents

Convection • Explains why breezes come from the ocean in the day and from the land at night

Radiation • Transfer of energy by electromagnetic waves • No movement of matter – will work in vacuum or outer space • No contact or movement of fluid • Infrared, visible light, UV rays

Radiation Example • Microwave Popcorn • Sun • Interior of car on a hot day

Conductors & Insulators • Conductor – Transfers thermal energy/heat well. • Insulator – Does not transfer thermal energy/heat well.

Thermal Expansion & Contraction • A material’s volume increase when the temperature increases. • A material’s volume decreases when the temperature decreases.

What type of heat transfer is involved? • Heating a room with a fireplace • Egg cooking in a frying pan • Roof of a house becoming hot