ATCS Ch2

Temperature

Measure of substance average kinetic energy

Heat

Energy transferred between objects due to a temperature difference.

3 ways to transfer heat

Conduction, Convection and Radiation

Conduction

Heat diffuses through an object, passing molecule to molecule

Convection

Transfer of heat by the mass movement of a fluid

Radiation

Heat transfer that does not require substances to touch or a fluid between them

Specific Heat

Heat capacity of a substance per unit mass

Latent heat

used to change phase of substance

If heat is released it

warms the surrounding air

If heat is absorbed

it cools the surrounding air

Vapor to liquid

condensation

liquid to solid

freezing

vapor to solid

deposition

solid to liquid

melting

liquid to vapor

evaporation

solid to vapor

sublimation

If something absorbs as much as it emits it is called a

blackbody

if something emits more than it absorbs it will

cool

if it absorbs more than it emits it will

warm

Gases that absorb in some wavelengths but not others are

Selective Absorbers

An objects albedo is the

percent of radiation returning from a given surface

earths albedio is

30%

The suns emission spectrum peaks at

0.5

Earth radiates nearly all of its energy between

5 and 25 um