MOTION

Average speed

The speed averaged for an entire journey.

Displacement

The distance that an object moves from its starting position.

Distance

The total length that an object travels.

Instantaneous speed

The speed at a particular time in a journey.

Speed

The distance an object travels divided by the time taken.

Velocity

A measure of how quickly displacement changes.

Acceleration

A change in speed over time.

Deceleration

A decrease in speed over time.

Balanced forces

Equal forces acting on an object that cancel out, maintaining motion.

Force

A push, pull, or twist, measured in Newtons (N).

Inertia

The property of matter that resists changes in speed or direction.

Mass

The amount of matter in an object, measured in grams or kilograms.

Unbalanced forces

Forces differing in size that do not cancel out, causing motion change.

Weight

A force acting downwards on a mass due to gravity.

Net force

The sum of all forces acting on an object.

Proportional

As one quantity increases, so does the other.

Inversely proportional

As one quantity increases, the other decreases.

Magnitude

The size of a measurement.

Normal force

The force of the ground pushing up in opposition to gravity.

Vector

A quantity that has direction and magnitude.

Accuracy

How close a measured value or experimental result is to the true or accepted reference value.

Reliability

The consistency and reproducibility of results obtained when an experiment or measurement is repeated under identical conditions.

Validity

The extent to which an experiment tests what it claims to test, and properly controls variables to address the research question.