posted by Lola .
A 50-kg box is being pushed a distance of 6.4 m across the floor by a force P with arrow whose magnitude is 154 N. The force P with arrow is parallel to the displacement of the box. The coefficient of kinetic friction is 0.24. 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. (The floor is level and horizontal. Forces that act on the box: pushing force P, frictional force f, normal force N, and weight mg.)
work done by push = 154 * 6.4 J positive
work done by friction = -50*9.81*.24*6.4 J negative
work done by normal = work done by weight = ZERO because force perpendicular to displacement