Walker, Halliday & Resnick — Kinetic Energy and Work: Problem 14

Figure 7-20 shows an overhead view of three horizontal forces acting on a cargo canister that was initially stationary but now moves across a frictionless floor. The force magnitudes are $F_1 = 3.00\text{ N}$, $F_2 = 4.00\text{ N}$, and $F_3 = 9.00\text{ N}$, and the indicated angles are $\theta_2 = 50.0^\circ$ and $\theta_3 = 35.0^\circ$. What is the net work done on the canister by the three forces during the first $4.00\text{ m}$ of displacement?