A.Energy is a concept that quantifies the amount of work previously done on an object as well as the amount of work than an object can perform (both of which are equal). B. Energy must always be transferred by the means of a physical force. C. All forces cause work from a macro perspective viewpoint. Forces can only be exerted by objects that have had work preformed on them previously. If the total energy in the whole universe was and will be constant through all time then does that mean that there is a fixed center of mass of the universe?