Pop Quiz: What chain needs to break for the brick to fall?

Now look at the other two chains:

Chain A connects the left end of the beam to the top of the post. If the left side rises, that chain actually becomes less important because the distance shortens rather than increases, so it does not stop the beam in the same way.

Chain C is attached on the right side, but when the brick side drops, the geometry causes that chain to loosen rather than hold the beam up. So it is not the chain preventing the brick from falling.

That means only Chain B is truly stopping the downward rotation caused by the brick’s weight.

Final Answer: B

This puzzle is a great example of how weight, leverage, and tension can be misleading at first glance. Many people instinctively pick the chain closest to the brick, but the real answer comes from understanding which chain resists the beam’s actual movement.

So if Chain B breaks, the right side drops, and the brick falls.