Speed

The distance traveled in a single unit of time

Velocity

An object's speed in a particular direction

Acceleration

Any change in an object's speed or direction.

Inertia

How much an object resists acceleration

Force

Any push or pull.

Balanced forces

When two or more forces act on an object at the same time, and they cancel each other out.

Unbalanced forces

When two or more forces are acting on an object, and one is not cancelled out by the other(s).

Observation

Information about an object or event that is collected using your senses, or tools that help your senses.

Inference

A conclusion you make based on observations and things you knew before.

Quantitative data

Data that includes numbers and units.

Qualitative data

Data that does not include numbers.

Scientific error

Differences in data when the same thing is measured repeatedly.

Newton's first law

An object will not change it's velocity or accelerate unless an unbalanced force acts on it.