# Homework Help: Torque and equilibrium; concept problem

1. Dec 2, 2008

### alpha372

1. The problem statement, all variables and given/known data

I'm just trying to understand why the force from net torque isn't included in net force when considering equilibrium: Why isn't the force from torque part of the net forces acting on a body?

2. Relevant equations
if net force = 0 and net torque = 0 then the body is in equilibrium;
net force = ma, torque = Frsin@, where @ is theta

3. The attempt at a solution
It seems like the force required for torque should be part of the net forces acting on the body.

2. Dec 2, 2008

### Staff: Mentor

"Net force" is not a force, it's the sum of individual forces. You can certainly have forces acting on something so as to create a net torque, yet those same forces add up to zero net force. For example: a vertical force to the right of center and an equal but opposite vertical force to the left of center.

And you can also have a net force on a body with zero net torque.

3. Dec 2, 2008

### alpha372

Agreed.

Your example helped me:
Thanks.

So from this I now believe that the force from the torque actually is considered in the net force acting on the object. Now I am starting to understand why both net force and net torque need to be included for equilibrium.

Last edited: Dec 2, 2008