Section 2 Conservation of Energy - Vocabulary Flashcards

Flashcards covering energy stores, energy transfer, dissipation, efficiency, and related concepts from the notes.

Kinetic energy store

The energy an object has due to its motion; for a moving object, KE = 0.5 × mass × (speed)² (measured in joules, J).

Thermal energy store

The energy stored by the random motion of particles within a substance; related to its temperature.

Chemical energy store

Energy stored in chemical bonds, released by chemical reactions (e.g., in fuels and food).

Gravitational potential energy store

Energy due to an object's height in a gravitational field; change in GPE = m × g × Δh.

Elastic potential energy store

Energy stored when an object is stretched or compressed (e.g., springs, rubber bands).

Electrostatic energy store

Energy stored in the electric field between charges that attract or repel.

Magnetic energy store

Energy stored in a magnetic field between magnets or electric currents.

Nuclear energy store

Energy stored in atomic nuclei released in nuclear reactions.

Conservation of energy

In a closed system, total energy remains constant; energy can be transferred or dissipated but not created or destroyed.

Closed system

A system with no net change in total energy; can be treated on its own without energy exchange with surroundings.

Energy transfer

The process of moving energy from one energy store to another.

Mechanical (work) transfer

Energy transferred by a force acting through a distance; e.g., pushing or stretching.

Electrical transfer

Energy transferred by electrical work in circuits via moving charges.

Heating transfer

Energy transferred from a hotter object to a colder object by heat (conduction, convection, or radiation).

Radiation transfer

Energy transferred by waves (electromagnetic radiation) without needing a medium.

Dissipation

Energy spreading out and becoming non-useful, often ending up as thermal energy in surroundings.

Efficiency

The ratio of useful energy transferred to total energy supplied; always less than 1 (or 100%).

Wasted energy

Energy transferred to non-useful stores and not contributing to the desired work.

Useful energy

Energy that ends up in a store that provides the intended or useful work.

Sankey diagram

A diagram showing energy transfers with arrows; arrow thickness indicates the amount of energy transferred.