Newton's first law

A body will remain at rest or continue to move in a straight line at a constant velocity unless an external force acts on it.

Brittle

A brittle material will break with little or no plastic deformation.

A closed system.

A closed system is any system in which all the energy transfers are accounted for.

Energy or matter cannot enter or leave a closed system.

Ductile

A ductile material can be drawn into wires and will show plastic deformation under tensile stress before breaking.

Hard

A hard material will resist plastic deformation by surface indentation or scratching.

Kilowatt-hour

A kilowatt-hour is the energy transferred by 100 W in 3600 seconds. It si therefore equal to 3,600,000 J.

Malleable

A malleable material can be hammered or beaten into flat sheets and will show extensive plastic deformation when subject to compressive forces.

Photon

A photon is a quantum associated with electromagnetic radiation.

Polymer

A polymer is a material made of long chains of molecules.

Potential divider

A potential divider circuit uses two resistors in series to split or divide the voltage of the supply in a chosen ratio so that a chosen voltage can be supplied to another device or circuit.

Progressive wave

A progressive wave is a wave that tranfers energy away from a source.

Quantum

A quantum is a small discrete unit of energy.

Scalar

A scalar quantity is one which has magnitude but not direction.

Systematic error

A systematic error is one that doesn't happen by chance, but as a result of an inaccuracy in the apparatus or its use by the person using it. This type of error tends to shift all the results in the same direction.

Vector

A vector quantity is one which has both magnitude and direction.

Vector triangle

A vector triangle is a type of scale diagram with two vectors drawn tip-to-tail, to show how they can be added together.

Zero error

A zero error is a type of systematic error caused by an instrument not being properly calibrated or adjusted. It then gives a non-zero value when the value should be zero.

Accuracy

Accuracy is a measure of the closeness of agreement between an individual test result and the true value. If a test result is accurate, it is in close agreement with the true value.

Anomalous value

An anomalous value in a set of results is one that does not fit the overall trend in the data. it is therefore discounted from any analysis.

Elastic collision

An elastic collision is one in which both the momentum and kinetic energy are conserved. No energy is transferred to other forms.

Inelastic collision

An inelastic collision is one in which the momentum is conserved but some of the kinetic energy is transferred to other forms.

Fiducial mark

An object placed in the field of view for an observer to use as a reference point.

Anti-nodes on a stationary wave

Anti-nodes on a stationary wave are points where displacement is a maximum.

Archimedes' principle

Archimedes' principle states that the upward buoyant force (upthrust) exerted on an object immersed in a fluid is equal to the weight of the fluid displaced.

Diffraction

Diffraction is the spreading out of a wave after passing around an obstacle or through a gap.

Elasticity

Elasticity is the property of a body to resume its original shape or size once ethe deforming force or stress has been removed.

Error

Error (of measurement) is the difference between an individual measurement and the true value (or accepted reference value) of the quantity being measured.

Hooke's Law

Hooke's Law states that the extension of an object is proprtional to the force that causes it, provided that the elastic limit is not exceeded.

Newton's third law

If object A exerts a force on object B, then object B will exert an equal and opposite force on object A.

Impulse

Impulse is the product of force and the the time for which the force acts.