Heat Transfer NOTES Thermal Energy TOTAL energy of

Heat Transfer NOTES

Thermal Energy • TOTAL energy of motion in molecules of a substance (therm=heat)

Temperature • Average amount of energy in motion * Measured with a thermometer

HEAT Energy Transfers… • from hotter object to COLDER object hot Heat cold

3 types of heat Transfer 1) Radiation: infrared (not visible) and FELT as heat, can be absorbed or emitted; example: the sun, heat from a fire, frying an egg. *Touch is NOT required!* 2) Conduction: transfer of heat by TOUCH, usually includes direct contact; example: when you touch a hot pot 3) Convection: transfer of heat by movement of molecules in a liquid/gas, no touch required, heat expands followed by cooling and contraction; example: typically how heat is transfered in the troposphere, water boiled in a pot, a convectoin (toaster) oven.

• Examples: Radiation (infrared) *Feel warmth on face from sun= solar radiation * Warmth of a fire * Heat off car engine

Conduction=touch • Examples: * Hot sand on feet * Touching hot light bulb • * Touching metal on hot seatbelt * Stove to pan handle * Melting ice in hand

Convection * Boiling in water * Convection oven

LOOK AT ALL THREE:

Heat Transfer in the Troposphere * 3. convection 1. RADIATION from the sun * CONVECTION is the most dominant heat transfer in the troposphere with the help of winds 2. Energy reaches the surface and is absorbed = CONDUCTION, then bounces back (rises)

Type Radiation Conduction Convection Definition Examples: