"For a system of particles, work and energy concepts were used only in examples in which it could be observed by other means that the kinetic energy of the system was conserver and in which the velocities of each of the particles could be determined. The most practicle applications were elastic collisions within a system of particles. Therefore, questions may arise as to the usefulness of the concept of work and energy when working with a system of particles. However, for a system of particles that form a rigid body, a work-energy concept can be developed that is as powerful as that used for a single particle." p484

CONSERVATION OF ENERGY
THE ENERGY OF A SYSTEM DOES NOT CHANGE. THE ENERGY AT THE START IS THE SAME AS THE ENERGY AT THE FINISH.

COUPLE
A PAIR OF EQUAL AND OPPOSITE FORCES THAT MAY CAUSE A ROTATION MOTION

ENERGY
THE ABILITY TO DO WORK. THE ENERGY OF THE UNIVERSE IS CONSERVED: ITS VALUE STAYS THE SAME OVER TIME.

FIXED POINT
A POINT THAT IS MAINTAINED AT A SET POSITION.

HOMOGENEOUS
HAVING THE SAME CONSISTENCY OR PROPERTIES THROUGHOUT.

HOMOGENEOUS
SAME COMPOSITION THROUGHOUT

POINT
A POSITION OR LOCATION IN SPACE