E.C. Physics 1 Final Review CH 9

System:

Any collection of objects, either pointlike or extended. In many momentum-related problems, you have a certain freedom in choosing the objects to be considered as your system. Making a wise choice is often a crucial step in solving the problem.

External force:

Any force interaction between objects at least one of which does not belong to the chosen system; in other words, at least one of the objects is external to the system.

Internal force:

Any force interaction between two objects belonging to the chosen system. Let us stress that both interacting objects must belong to the system.

There must be equal amounts of mass on both side of the center of mass of an object.

False

The quantity ma (mass times acceleration) is dimensionally equivalent to what?

Force

Total momentum:

The vector sum of the individual momenta of all objects constituting the system.

Closed system:

a system that is not subject to any external forces.

A baseball is thrown vertically upward and feels no air resistance. As it is rising a. both its momentum and its kinetic energy are conserved. b. its momentum is not conserved, but its mechanical energy is conserved. c. both its momentum and its mechanical energy are conserved. d. its gravitational potential energy is not conserved, buts its momentum is conserved. e. its kinetic energy is conserved, but its momentum is not conserved.

b. its momentum is not conserved, but its mechanical energy is conserved.

Acceleration is due to which of the following physical quantities? velocity speed energy momentum force

force