Material has weight?

Why does my material have weight?
What I mean is, I have a plane, mesh, material. On that I have a hinge joint. The anchor is towards the bottom right corner. I have no rigid body on it. It is attached, via the hinge to another object. When I run the game, the foot( the object in question), rotates around the hinge, like it is a slave to the mass of the material. However, I thought materials would have no mass what so ever. I thought it would just hang from its hinge.

 

Another note is,
Is it possible a collider collides with and knocks over a mesh?

 

Edit.
Just solved.

Thanks.