Chapter 11, Problem 9P

Two forces ${\stackrel{\to }{F}}_1$ and ${\stackrel{\to }{F}}_2$ act along the two sides of an equilateral triangle as shown in Figure P11.5. Point O is the intersection of the altitudes of the triangle. (a) Find the magnitude of a third force ${\stackrel{\to }{F}}_3$ to be applied at B and along BC that will make the total torque zero about the point O. (b) What If? Will the total torque change if ${\stackrel{\to }{F}}_3$ is applied not at B but at any other point along BC?

Figure P11.5