This document defines key concepts related to forces. It explains that a force is a push or pull that can change an object's motion, having both magnitude and direction. Friction is defined as a force that opposes the motion of objects in contact. The net force is the combination of all forces acting on an object. Balanced forces cancel out, resulting in no change to motion, while unbalanced forces change an object's motion by starting, stopping, or altering its speed or direction. Inertia and Newton's Second Law are also introduced.
6. Balanced Force
A set of forces on an object that
cancel one another out so that
there is no overall force on that
object;
the combined force is the same as
zero force;
balanced forces will not cause a
change in the motion of an object
7. Unbalanced Forces
A set of forces exerted on an object
that change the motion of that
object
The combined for has size
(magnitude) and direction
Unbalanced forces are needed to
make an object start moving, speed
up, slow down, or change direction
8. Inertia
The tendency of an object to
resist being moved or, if the
object is moving, resist a
change in speed or direction
