How can we prove that the forces acting on a body can form a closed-up

1. Nov 24, 2011

asdff529

How can we prove that the forces acting on a body can form a closed-up polygon?

2. Nov 25, 2011

McLaren Rulez

Re: Equilibrium

If they didn't, then there would be a resultant force. The magnitude of the resultant is zero only if the other forces form a closed polygon. The condition for equilibrium is, of course, no net force

3. Nov 25, 2011

JHamm

Re: Equilibrium

If there are no forces or only two forces on the object then that object could be in equilibrium but the force vectors can't be connected to form a polygon.

4. Nov 25, 2011

McLaren Rulez

Re: Equilibrium

Well you could think of the two forces case as going along a line and back along the same line.

The idea to remember is that the sum of the force vectors is a zero vector for the object in equilibrium.