7. A sail boat moving through a river has two forces acting upon it, as shown below. (Scale is in Newtons (N).) Add the two forces, using tail-to-head vector addition, to find the resultant force (magnitude and direction). 80 po W E 80 60 40 20 20 40 60 80 20 40 50 ANSWERS: Multiple choice 1b, 2c, 3b, 4d, 5b, 6c, 7d, 8a, 9b, 10b, 11c, 12b, 13d, 14c, 15d, 16c True/False: 1a)T b)T c)F d)F 2a) F b)T c)T d)F 3a) T b)F c)F d)T 4a) F b)F c) F d) F Calculation: 1) 5s, 20m/s, 2) -5 m/s2, 160m, 4 times greater 3) 1.0 m N37.E 4) 1.22m, 5) 11.55 m, 2s, 5m