Edexcel GCSE Physics key terms

Electromagnetic radiation immediately beyond violet in the spectrum, with a shorter wavelength and higher frequency than visible light.

Forces that combine to give a non-zero resultant force.

A nucleus that has not yet undergone radioactive decay.

Acceleration that remains constant; it appears as a straight line on a velocity–time graph. A horizontal line represents uniform acceleration of zero.

Motion along a circular path at constant speed.

A field with the same strength and direction at every point in the region considered.

A magnetic field that has the same strength and direction at every point in the region considered.

A standard used to express a measurement, such as the second for time or the metre for length.

Charges of opposite types: one positive and one negative.

A nucleus that can spontaneously emit radiation and change into a more stable nucleus.

An energy transfer that spreads energy into the surroundings where it is less useful for the intended purpose.

The resultant upward force exerted by a fluid on an object within it.

A particular form of uranium whose nucleus contains 92 protons and 143 neutrons, giving a mass number of 235.

An energy transfer that produces the output wanted from a device or process.

Energy transferred in the form or to the store required for the device's intended purpose.

A region containing no matter.

A resistor whose resistance can be adjusted, allowing the current and potential difference in a circuit to be changed safely.

A quantity that has both a size and a direction.

An arrow used to represent a vector: its orientation and arrowhead show direction, while its length can show magnitude when drawn to scale.

A physical quantity that has both magnitude and direction.

Velocity is speed in a stated direction.

A graph that shows how an object's velocity changes with time, with velocity on the vertical axis and time on the horizontal axis.

The back-and-forth movement of an object or part of a material about its resting position.

An image formed where light rays appear to come from, found by extending the outgoing rays backwards. It cannot be projected onto a screen at that position.

Electromagnetic radiation that can be detected by the human eye.

The continuous range of colours within visible light, from red to violet.

The unit of potential difference, with symbol V; one volt is one joule per coulomb.