Heat and Thermodynamics Rachel Sandman Kristen Schlotman Kiara Sierra Physics, period 6

Temperature Temperature tells how hot or cold something is. Three scales: Celsius, Fahrenheit, and Kelvin.

Heat and Internal Energy Heat always flows from higher temperature substances to lower temperature substances.

Measurement of Heat The units for heat are the calorie and the kilocalorie (1000 calories).

Specific Heat Capacity Different substances have different capacities for storing internal energy.

Thermal Expansion An increase in heat causes an expansion of the substance. An example is a thermostat’s bimetallic strip.

Conduction Heat is transferred through objects by conduction. Metals are the best conductors.

Insulation Insulators delay the transfer of heat. Liquids and gases in general are good insulators.

Convection Through convection, heating occurs by currents in a fluid.

Radiation The sun’s heat is transmitted through radiation. Energy transmitted by radiation is called radiant energy.

Newton’s Law of Cooling The rate of cooling of an object is approximately proportional to the temperature difference between the object and its surroundings.

Phase Changes Evaporation (liquid to gas) Condensation (gas to liquid) Boiling (liquid to gas) Freezing (liquid to solid)

First Law of Thermodynamics Whenever heat is added to a system, it transforms to an equal amount of some other form of energy.

Second Law of Thermodynamics Heat will never of itself flow from a cold object to a hot object.

Entropy Entropy is the measure of the amount of disorder. As disorder increases, entropy increases.