Question

If we keep objects on a sample bridge in a balanced way, the bridge does not collapse and if not balanced, it collapses. Give reason.

Answer 1

Dear Student,
This is happen because of centre of mass of the bridge. The centre of mass is the point where all of the mass of the object is concentrated. When an object is supported at its centre of mass there is no net torque acting on the body and it will remain in static equilibrium.
Position of centre of mass is fixed with respect to the body as a whole. This point may or may not be within the body. The position of the centre of mass of a rigid body depends upon the shape and distribution of mass in the body. So, when we keep objects on a sample bridge in a balanced way the bridge will not collapse and if we keep object in unbalanced way then the bridge will collapse.
Regards