In a tug-of-war game on one campus, 15 students pull on a rope at both ends in an effort to displace the central knot to one side or the other. two students pull with force 196 n each to the right, four students pull with force 98 n each to the left, five students pull with force 62 n each to the left, three students pull with force 150 n each to the right, and one student pulls with force 250 n to the left. assuming the positive direction to the right, express the net pull on the knot in terms of the unit vector. how big is the net pull on the knot? in what direction?