forces in motion

3. the rate at which something is moving
4. acts on something moving in a circular path and directed toward the center
7. speed of something in a direction
9. force that keeps an object at rest
10. two forces are the same but are going in opposite directions
12. resistance that an object encounters when moving over another
14. rate of change of velocity
16. quantity of motion that is measured with mass and velocity
17. moving from its place or position
19. a well-substantiated explanation of an aspect of the natural world that can incorporate laws, hypotheses and facts
20. Net force that is equal to mass times acceleration

1. force that acts in the opposite direction while an object is moving through the air
2. relative mass or quantity of matter
5. a scientific procedure undertaken to make a discovery, test a hypothesis, or demonstrate a known fact
6. for every action there is an equal and opposite reaction
8. resistance created by two objects sliding together
11. a method of procedure that consists of systematic observation,measurement, experiments, the formulation,testing,and modification of hypotheses
13. push or pull on an object
15. force that attracts a body towards the center of the Earth
18. remains at rest unless a force acts on it