Physics key terms

The change in the energy stored within a material as it is heated or cooled, measured in joules (J).

The final momentum minus the initial momentum; for an object of constant mass, $\Delta p=m(v-u)=m\Delta v$.

The difference between the final and initial temperatures: $\Delta\theta=\theta_{\text{final}}-\theta_{\text{initial}}$.

The change in energy stored thermally when the temperature of a system changes, measured in joules (J).

The upward or downward difference between two positions, measured vertically rather than along the route taken.

A physical change in which a substance changes between the solid, liquid and gas states without becoming a different substance.

The quantity of electric charge transferred, measured in coulombs (C).

The quantity of electric charge that passes a point, measured in coulombs (C).

The transfer of electrons between materials when their surfaces are rubbed together.

A change that forms one or more new substances with different properties.

The energy stored in a battery's chemicals that decreases as the battery powers a device.

A safety switch that automatically opens a circuit when it detects an excessive current.

A part of an electrical circuit, such as a cell, switch, lamp, resistor or motor.

A drawing that uses standard symbols and lines to show how electrical components are connected.

A computer-based representation of the climate system used to test explanations and make predictions.

A complete, unbroken conducting path through which electrical charge can flow.

A fixed quantity of gas from which no particles enter or escape.

A system across whose boundary no energy is transferred to or from the surroundings.

The fluid-filled structure in the inner ear where vibrations are converted into nerve signals.

A loop or winding of conducting wire through which current flows.

Detection of two gamma-ray photons from the same annihilation event at almost the same time.

An event in which objects strike one another and exert forces on each other.

The number of collisions occurring in a given time.

A material that transmits one or more ranges of visible wavelength and absorbs others.

A material that transmits some wavelengths of visible light and absorbs others.

A small, icy body that orbits the Sun and can develop a cloud of gas and dust, and a tail, as it approaches the Sun.

A small magnet that can turn freely to align with the magnetic field around it.