1. Find the resultant of the following vectors by the polygon method: D1 = (450 N, 150 degree), D2= (200 N,270 degree), D3 = (300 N, 135 degree).
2. A girl wraps a rope around a tree and ties one end to a wall. When she pulls the other end of the rope with a force of 30 lb, the ends of rope make a 60 degree angle. Assuming the tension in the rope tied to the wall is 20 lb and that the rope does not slip, find the resultant force on the tree using the parallelogram method.
3. A cable is wrapped around a steel beam so that it will not slip. The ends of the rope make a 90 degree angle. One end of the cable exerts a force of 320 lb, and the other exerts a force of 416 lb. What is the magnitude of the resultant force on the beam?