Describing Motion and Forces

Net Force

The combination of all the forces acting on an object.

Balanced Forces

Forces acting on an object that combine to form a net force of zero; they do not cause a change in motion.

Unbalanced Forces

Forces that do not cancel each other out, resulting in a change in motion of the object.

Reference Point

An object used for comparison to determine whether something is in motion.

Relative Motion

The concept that motion is determined by a reference point that can change, making motion dependent on that reference.

Motion

An object is in motion if its distance or position changes compared to another object.

Force

A push or pull acting upon an object.

Direction

The path along which something moves or points.

Change in Motion

The alteration in an object's position as a result of the net forces acting on it.

Cumulative Force

The total force resulting from adding individual forces acting in the same direction.

Opposing Forces

Forces acting in opposite directions that can be combined to determine net force.