posted by emerald .
A figure shows two forces acting on an object. They have magnitudes F1 = 6.3 N and F2 = 2.1 N. What third force will cause the object to be in equilibrium?
It will depend upon the directions of the forces F1 and F2. Add them as vectors and then reverse the direction of the resultant. That will the vector that causes equilibrium.
It is called the equilibrant vector