$1-7$ Cold air at $10$ C flows across the outer surface of a $\backslash (1\mathrm{.}5-\backslash$mathrm$\{$cm$\}\backslash )$ OD tube. The surface of the tube is kept at a constant temperature of $120$ C $.$ If the convective coefficient between the outer surface of the tube and the air is $70$ W$/$m$2$ C$,$ what is the convective heat transfer per meter length of tube $($W$/$m$)?$