A cylindrical pressure vessel is constructed with AL-6XN stainless steel alloy metal for
cryogenic storage capacity. The main body of the pressure vessel takes the shape of a
cylinder with radius r and height (or length) h. In order for the pressure vessel to be installed
properly at the industrial site, the pressure vessel dimensions must satisfy the requirement
that the sum of the height (or length) plus ten times the radius should equal 60 m.
What dimensions r and h produce a pressure vessel with the largest volume storage capacity?