A hemisphere whose diameter is 4cm, made of wood . If the a cone cut out of this hemisphere whose base is also 4cm . Find the volume of wood in hemisphere .
An open cylindrical vessel of internal diameter 7 cm and height 8 cm stands on a horizontal table. Inside this is placed a solid metallic right circular cone, the diameter of whose base is 312 cm and height 8 cm. Find the volume of water required to fill the vessel. If this cone is replaced by another cone, whose height is 134 cm and the radius of whose base is 2 cm, find the drop in the water level.
From a cubical piece of wood of side 21 cm, a hemisphere is carved out in such a way that the diameter of the hemisphere is equal to the side of the cubical piece. Find the surface area and volume of the remaining piece.