$2.)$You are pumping liquid nitrogen at a

temperature of $-206^($@$)$C through a long, horizontal, thin$-$walled

pipe; ignore the resistance of the pipe material and assume that

the outside temperature of the pipe is the same as the liquid

nitrogen. The pipe has an OD $15\mathrm{.}0$cm ; and is buried in the

ground $($k$=0\mathrm{.}52$W$//($m$-$k$),$ground surface temperature $=24\mathrm{.}0^($@$)$C $)$

at a depth of $2\mathrm{.}65$meters $($distance from the surface of the

ground to the centerline of the pipe$).$Determine the heat

transfer rate per unit length of the pipe. Use table $4\mathrm{.}1.$