A 55.0−kg box is being pushed a distance of 7.84 m across the floor by a force P→ whose magnitude is 180 N. The force P→ is parallel to the displacement of the box. The coefficient of kinetic friction is 0.209. Determine the work done on the box by each of the four forces that act on the box. Be sure to include the proper plus or minus sign for the work done by each force. (a) Wp = (b) Wf = (c) Wmg = (d) WN =