Physics Unit 3

Caloric Theory

Thought to be a fluid which flowed from hot objects to cold ones

• The theory was abandoned when it could not explain the heating of the drill and the cannon

Kinetic Molecular Theory (KMT)

• All matter is made up of particles that are always in motion

• hot objects have more motion/Ek

Thermal energy

• Defined as EK + EG of all particles

• Mass dependent

Heat

the transfer of thermal energy

Temperature

• The measure of the avg Ek of the atoms or molecules of a substance

• not mass dependent

Celsius to Kelvin Conversion

T = Tc + 273.15

Celcius to Fahrenheit

Tf = 1.8 x Tc + 32 degrees

Type of heat transfer: Conduction

when heat moves through material by direct contact between particles (mostly effective in solids)

Type of heat transfer: Convection

• When heat transferred by movement of fluids (liquids/gases)

• Warmer fluids less dense rise, cool then sink (water cycle)

Type of heat transfer: Radiation

When heat travels as electromagnetic waves, so it doesn’t need a medium

!st Law of Thermodynamics

• The law of conservation of energy

• The energy of an isolated system is consistent

2nd Law of Thermodynamics

• An isolated system will always progress toward thermal equilibrium

• Thermal energy is always transferred naturally from an object at a higher temp to an object at a lower temp until equilibrium is reached