Which of the following statements about work isor are true? (More than one statement may be true.)A. Negative net work done onan object always reduces the object's kinetic energy.B. If the work done on an object by aforce is zero, then either the force or the displacement must havezero magnitude.C. If a force acts downward, it doesnegative work.D. The formula W=Fdcos? canbe used only if the force is constant over the distance.
