The motion of an object can be described by its position, direction of motion, and speed. That motion can be measured and represented on a graph.
An object that is not being subjected to a force will continue to move at a constant speed and in a straight line.
For Grades: 9-12
Motions and Forces
Objects change their motion only when a net force is applied. Laws of motion are used to calculate precisely the effects of forces on the motion of objects. The magnitude of the change in motion can be calculated using the relationship F = ma, which is independent of the nature of the force. Whenever one object exerts force on another, a force equal in magnitude and opposite in direction is exerted on the first object.