Energy, Work, and Power Vocabulary

Vocabulary flashcards covering energy stores, transfer pathways, conservation laws, energy resources, and the mathematical definitions of work and power.

Energy

The ability to do work, measured in the SI unit Joule ($J$).

Kinetic energy ($E_K$)

The energy of motion, defined by the formula $E_K = \frac{1}{2}mv^2$ where $m$ is mass and $v$ is velocity.

Chemical potential energy

Stored energy in chemical bonds of substances, such as wood, coal, and oil.

Elastic potential energy

Energy stored in elastic materials.

Gravitational potential energy

Energy stored in objects higher than ground level.

Nuclear potential energy

Energy stored in the nucleus of atoms that is released in nuclear reactions.

Electrostatic energy

Energy stored when repelling charges have been moved closer together or when attracting charges have been pulled further apart.

Internal (thermal) energy

Heat energy stored in objects.

Mechanical work (transfer pathway)

An energy transfer pathway occurring when a force acts on an object.

Electrical work (transfer pathway)

An energy transfer pathway involving a charge moving through a potential difference.

Heating (transfer pathway)

The transfer of energy moving from hotter areas to colder areas.

Radiation (transfer pathway)

Energy transferred from electromagnetic waves such as light.

Principle of conservation of energy

The law stating that energy cannot be made or destroyed, but can only be transferred from one form to another.

Sankey diagrams

Visual representations of energy conservation showing input energy, useful output energy, and wasted output energy.

Work done

A value equal to energy transferred, calculated as Force ($N$) $\times$ distance ($m$) and measured in Joules ($J$).

1 Joule ($J$)

The equivalent of $1 \text{ Nm}$ ($Newton \text{-} meter$).

Fossil fuels

Non-renewable fuels like coal, petrol, wood, and natural gas that contain chemical energy and release heat when burned.

Biofuels

Renewable fuels derived from living matter (plants, algae, or animal waste) burned to produce steam for electricity generation.

Photovoltaic energy

Energy generated by solar cells converting light energy from the Sun into electrical energy.

Geothermal resources

Renewable energy obtained by using steam from water that boils naturally in underground hot springs.

Nuclear fission

A process where the nucleus of an unstable atom splits into two, releasing heat energy used to drive turbines.

Hydroelectric energy

Energy generated by releasing water stored at a height to turn turbines.

Nuclear fusion

A nuclear reaction in which atomic nuclei of low atomic numbers fuse to form a heavier nucleus, releasing energy.

Efficiency

The percentage of useful energy/power output over the total energy/power input.

Power ($P$)

The work done or energy transferred per unit time, calculated as $P = \frac{W}{t}$ or $P = \frac{\triangle E}{t}$, measured in watts ($W$).