chapter 2 vocab

2. the amount of matter in an object
5. when one object exerts a force on a second object, the second object exerts an equal force in the opposite direction on the first object
7. the push or pull on an object
10. the tendency of an object to resist moving
11. any motion in which an object is moving along a curved path
15. forces acting on an object that have a net force that add up to zero
17. push or pull on an object that is not touching it
19. the acceleration of an object is equal to the net force acting on the object divided by the object's mass

1. the total momentum of a group of objects stays the same unless outside forces act on the objects.
3. in circular motion, a force that acts perpendicular to the direction of motion, toward the center of the curve
4. a combination of all the forces acting on an object
6. the amount of force gravity is putting on an object
8. an invisible force that exists between all objects that have mass
9. forces acting on an object that have a net force that don't add up to zero
12. the net force of an object is zero, the motion of the object dose't change
13. is a measure of how hard it is to stop a moving object
14. a force between objects that are touching each other
16. the forces two objects apply to each other
18. Push or pull by an object that is touching it