Chapter 12, Problem 12E

A body is subject to three forces; ${\stackrel{\to }{F}}_1=1\hat{i}+2\hat{j}$N, applied at the point x = 2m, y = 0 m; ${\stackrel{\to }{F}}_2=-2\hat{i}-5\hat{j}$N, applied at x = −1 m, y = 1 m; and ${\stackrel{\to }{F}}_3=1\hat{i}+3\hat{j}$N, applied at x = −2 m, y = 5 m. Show that (a) the net force and (b) the net torque about the origin are both zero.