How to simulate objects hanging on a cord?

I’m a total newbie to Blender and I have a tiny bit of 3D modeling experience, but nothing serious. I’m trying to figure out how I can simulate (100% accurately) a rigid metal object hanging from a cord. See screenshot below:

I’ve got this set up so that the pendant is hanging on a rod. I just don’t know how to set these two objects up so that I can hit play and see how the object will hang in real life.

Any help would be greatly appreciated!