What fraction of the volume of a solid piece of metal of S.G. = 6.50 floats above the surface of a container of mercury of S.G. = 13.57? A rectangular open box, 6.5 m by 3.5 m in plan and 4 m deep,...

What fraction of the volume of a solid piece of metal of S.G. = 6.50 floats above the surface of a container of mercury of S.G. = 13.57?

A rectangular open box, 6.5 m by 3.5 m in plan and 4 m deep, weighs 360 kN and is launched in fresh water. (a) How deep will it sink? (b) If the water is 4 m deep, what weight of stone placed in the box will cause it to rest on the bottom?