Forces & Motion Review

8. The rate at which velocity changes over time.
10. For every action, there is an equal and opposite reaction.
12. The friction that occurs when an object rolls over a surface.
14. An object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.
16. The amount of matter in an object.
17. The force of gravity on a person or object at the surface of a planet.
18. Speed in a given direction.
20. The friction that acts on objects that are not moving.

1. The friction that occurs when two solid surfaces slide over each other.
2. The state in which one object's distance from another is changing.
3. A measure of the steepness of a line or a hill.
4. The acceleration of an object is dependent upon two variables - the net force acting upon the object and the mass of the object.
5. The force that pulls objects toward each other.
6. The tendency of an object to resist a change in motion.
7. The overall force on an object when all the individual forces acting on it are added together.
9. The friction that occurs when a solid object moves through a liquid or gas.
11. The distance an object travels per unit of time.
13. A push or pull on an object.
15. A system of objects that are not moving with respect to one another.
19. A force that opposes motion between two surfaces that are in contact.