A circular cylinder $x^2+y^2<4$ ; has base radius $2$ and height $3,$ with its bottom base on the xy$-$plane. Let its density at any point be given by p$($x$,$y$,$z$)=$z$.$ Find the center of mass of this cylinder$0$ has base radius $2$ and height $3,$ with its bottom base $on$ the $xy-$plane. Let its density $at$ any point $be$ given $byp(x,y,z)=z.$ Find the center $of$ mass $of$ this cylinder