Physics key terms

An action produced following a stimulus, such as closing the fingers to catch a ruler.

The force exerted by a distorted spring towards its original shape.

The single overall force that has the same effect as all the forces acting on an object together.

The overall turning effect of all the forces acting on an object.

The apparent backwards movement of a planet against the background stars for part of its journey across the sky.

The connection of a diode in the direction in which it has a very high resistance and allows almost no current to flow.

A change that can be undone so that the original material and its properties are recovered.

A rule for finding the magnetic-field direction around a current-carrying wire: point the right thumb in the direction of conventional current, and the curled fingers show the field direction.

A shallow tray of water used to produce and observe water waves.

The chance that a hazard will cause harm, considered together with how serious that harm could be.

The process of identifying hazards, considering the associated risks and selecting measures to reduce them.

A factor associated with an increased probability of an unwanted outcome, without necessarily producing that outcome in every case.

Movement in which an object turns around a fixed point or axis.

Replacing a number with a nearby value expressed to a chosen level of precision.

The total time taken for a wave to travel to a reflecting surface and return.

The number of measurements or distinct items included in an investigation, stated clearly for the context.

A diagram in which one input arrow divides into output arrows whose widths are proportional to the amounts of energy transferred.

An object that orbits another object; satellites can be natural or artificial.

A quantity with a size, or magnitude, but no direction.

A quantity with a magnitude (size) but no direction.

A drawing in which measured arrow lengths represent vector magnitudes according to a stated scale.

The redirection of light in many directions, for example by a rough surface or within a translucent material.

The exchange of scientific findings and viewpoints in ways that an audience can understand and use.

An account of how or why a particular event or phenomenon occurs, often produced by applying a scientific theory to that situation.

A simplified representation used to describe and explain observations; it may be changed or replaced when new evidence does not fit it.

A question that could, in principle, be investigated using observations or measurements.

A general explanation that has been tested and used successfully across many situations.