Energy & Heat

Energy

The capacity of an object to do work.

Potential energy

The energy an object possesses due to its position or shape.

Kinetic energy

The energy of an object due to its motion.

Gravitational potential energy

Potential energy held in an object due to its gravitational attraction to another object.

Elastic potential energy

Potential energy stored in an elastic object due to the application of force that deforms it.

Mechanical energy

The sum total of an object's gravitational potential energy, elastic potential energy, and kinetic energy.

Law of conservation of energy

Energy cannot be created or destroyed, but can be changed from one form to another.

Heat transfer

The transfer of kinetic energy from one medium or object to another.

Conduction

Heat transfer that occurs when particles are in direct contact and have different temperatures.

Convection

Heat transfer that occurs in liquids and gases when molecules carrying energy rise, cool, and sink, creating a continuous cycle of heat transfer.

Radiation

Heat transfer through electromagnetic waves.

Exothermic reaction

A reaction that generates heat and releases it to the surroundings.

Endothermic reaction

A reaction that absorbs heat from the surroundings.

Temperature

The measure of the kinetic energy of the molecules in an object.

Absolute zero

The lowest possible temperature, where particles stop moving altogether.

Specific heat

The amount of energy required to raise the temperature of 1 kg of a substance by 1°C.

Fossil fuels

Nonrenewable natural fuels formed from the remains of living organisms, such as coal, oil, and natural gas.

Nuclear power

A nonrenewable source of energy associated with nuclear fission.

Renewable energy sources

Energy sources that can be replenished, such as hydroelectric power, solar power, and wind power.

Photovoltaic cells

Devices made of treated silicon used to convert solar energy into electrical energy.