Forces and Newton's laws

1. Force: to push or pull exerted by one object on another.
2. Friction: a force that opposes the motion of an object in contact with a surface.
3. Drag force: a force that opposes the motion of an object through a liquid or gas.
4. Gravity: a force of attraction that exist between all objects with mass.
5. Net force: the combined effect of all forces acting on a object.
6. Balanced force: forces that cancel each other out when acting together on a single object.
7. Unbalance force: forces that do not cancel each other out when acting together on a singel object.
8. Inertia: the tendency of an object to oppose a change in motion.