Chapter 12

2. a force that opposes the motion of objects that touch as they move past each other
6. law stating that the total momentum of a system does not change if no net force acts on the system
7. the force of gravity acting on an object
9. the constant velocity of a falling object when the force of air resistance equals the force of gravity
14. a push or a pull that acts on a object
15. a friction force that opposes the motion of an object through a fluid
17. a friction force that acts on objects that are not moving

1. a frictional force that acts on rolling object caused by the change in shape at the point of rolling contact
3. the SI unit for force
4. the curved path of an object in free fall after it is given an initial forward velocity
5. the product of an object’s mass and its velocity
8. a friction force that opposes the motion of an object as it slides over a surface
10. the amount of matter in an object a measure of the inertia of an object, which depends on the amount of matter the object contains
11. fluid friction acting on an object moving through the air
12. the tendency of an object to resist a change in its motion
13. the overall force acting on an object after all the forces are combined
16. the attraction between any two objects because of their masses