To help move heavy pieces of furniture across the floor move

To help move heavy pieces of furniture across the floor, movers sometime employ a body harness similar to that used for a plow horse. A mover applies a constant 200-lb force to drag a piano 100 foot down a long hallway and into another room. If the straps make a 40 degree angle with the direction of movement, find the amount of work performed.

Solution

Force along the horizontal direction = Fcos40 = 200*cos40 =153.21 lb

Work done = force x displacement = 153.21 x 100 = 15,321 ft-lb