OCR GCSE Physics A key terms

Shaping an object so that it experiences less resistance as it moves through a fluid such as air.

A deformation in which forces pull different parts of an object apart, increasing its length.

A change directly from a solid to a gas without passing through the liquid state.

A powerful explosion near the end of a massive star’s life.

A transverse seismic wave in which particles vibrate across the direction of travel; it travels through solids but not liquids.

A component that opens or closes a conducting path to stop or allow current.

A group of interacting objects treated together when analysing momentum.

A straight line that touches a circle at one point. The instantaneous velocity of an object in circular motion is directed along a tangent.

A measure related to the average kinetic energy of the particles in a substance.

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

The pulling force transmitted through an object such as a rope, cable or stretched spring.

The constant velocity reached when resistive forces balance the force driving an object's motion, making the resultant force and acceleration zero.

A measure of how readily a material conducts thermal energy; a lower thermal conductivity means it is a poorer conductor.

Energy associated with the temperature of an object or system.

A material or layer used to reduce thermal energy transfer.

Electromagnetic radiation emitted by a body because of its temperature.

The energy store associated with the movement and arrangement of particles in an object.

An image made using infrared radiation that shows differences in the surface temperatures of objects.

The distance travelled during the driver's reaction time, before braking begins.

The time a driver takes to recognise a hazard, react and apply the brakes.

The duration between two events, measured in seconds (s).

The duration of an event or journey, commonly measured in seconds.

The complete length of the route travelled, irrespective of direction.

All the energy supplied to a device or process.

The complete elapsed time from the start to the end of the motion, including any stops that are part of the journey.

A device that changes an alternating potential difference between its input and output coils.

The passage of electromagnetic radiation through a substance.