# Rotational force

1. Homework Statement

Beverage Engineering. The pull tab was a major advance in the engineering design of beverage containers. The tab pivots on a central bolt in the can's top. When you pull upward on one end of the tab, the other end presses downward on a portion of the can's top that has been scored. If you pull upward with a 10 N force, approximately what is the magnitude of the force applied to the scored section?

2. Homework Equations

3. The Attempt at a Solution

Now at first I thought that the force down just had to be the opposite of the force up, which would be -10 N. But I didn't think this problem could be that easy...

So since the tab pivots on a central bolt the torque=inertia * angular acceleration (newtons second law)
Now we don't know the mass of the can, so we cannot find inertia or acceleration. I think that since there is nowhere to go, it must be -10 N? I just can't see the problem being that simple

Thanks! Any push in the right direction would be great.