Scale

In an ideal world, 200n.

@Bruce McCrory,

That's what I say, but I posted this on Facebook, and most said zero. Hmmm. Can anyone articulate WHY it would be 200? I think they must be assuming the scale centers at zero and can move either direction.

To me, the scale does not look like it would center.  The right side hanger looks to be for hanging the scale vertically, while the left side hook is for hanging the object to be weighed, like a fish scale.

The scale would read 100 N, however.  If there were 200 N of tension in the scale and the lines connected to it, the blocks would both lift.  

If the weight on the right were not there, and you were holding the scale with your finger, you would be applying 100 N of force to the right to keep the weight on the left from falling.  In this case, the weight on the right is providing that 100 N of force.

Jason