Oil flows through a horizontal pipe with an inner diameter of D$=0\mathrm{.}02,$and length of L$=5$m$.$ A uniform heat flux of q$=800$W$/$m$2$q$\text{'}\text{'}$ is applied to the pipe wall. The inlet temperature of the oil is Tin$=20$C and the average flow velocity is um$=0\mathrm{.}2$m$/$s$.$

A$-$ Calculate the Reynolds number and determine whether the flow is laminar or turbulent.

B$-$ Using an appropriate correlation for fully developed flow with constant heat flux, calculate the average heat transfer coefficient.

C$-$ Find the temperature of the oil at the outlet of the pipe.