"Work" problem I'm sure this is a straight forward problem, but I think that I may be taking the wrong approach. Any guidence would be appreciated. Problem: In many neighbourhoods, you might see parents pulling youngsters in a four-wheeled wagon. The child and the wagon have a combined mass of 50 kg and the adult does 2.2*10^3 J of work pulling the two for 60 m at a constant speed. The coefficient of friction for the surfaces in contact is 0.26. a) Draw an FBD for the wagon (Not a problem) b) Determine the magnitude of the force applied by the parent. c) Determine the angle at which the parent is applying this force. For b) Since speed is constant F(net) = 0. Therefore, F(a) - F(f) = 0, F(a) = F(f) F(f) = u(k)F(n) = 0.26((490 N) = 127.4 N So...the magnitude of the force applied by the parent is 127.4 N? For c) Since W = Fd 2.2*10^3 = 127.4 N cos theta (60 m) = 7644 J cos theta cos theta = 2200 J/7644 J = 0.2878 theta = 73.3 degrees. So...the angle at which the parent is applying this force is approximately 73.3 degrees?