Forces are vector quantities with units of Newtons (N); 9.8 N of force are required to support 1.0 liter of water near the surface of the Earth. In this question, you eventually have to add three forces acting on a particular object so as to find the total force acting on that object. A large log is located on the icy surface of a frozen pond; for this problem, the ice may be assumed to be a frictionless surface. Three ropes have been attached to the log; three boys are planning to have a sort of tug-of-war by standing on the shore of the pond and pulling on the ropes. The ropes are all horizontal. Ignore the vertical forces on the log, which are the force of gravity on the log by the Earth, and the contact force on the log by the ice. Your job is to add the three horizontal forces to find the total horizontal force acting on the log.