42. Three solid balls are placed in the x-y plane as shown in Fig- ure P9.42. Find the net gravitational force on the ball at the origin. y (m) 0.40 kg at 1.3 kg at (-0.35 m, 0.18 m) (0.21 m, 0.40 m) x (m) FIGURE P9.42 0.75 kg at (0,0)