A steel plate $$40cm \times 30cm \times 0.3cm$$ is to be cast. The volume shrinkage of steel during solidification is $$3\% .$$ A cylindrical side riser with diameter $$4cm$$ and height $$4cm$$ is used. The riser volume should at least be $$3$$ times that the dictated by shrinkage consideration. Is the riser volume sufficient if not what is the riser size?