Air is flowing steadily through a horizontal tube at a constant temperature of $32^{\circ} \mathrm{C}$ and a mass flow rate of $1 \mathrm{~kg} / \mathrm{s}$. At one point upstream where the tube diameter is $50 \mathrm{~mm}$ the pressure is $345 \mathrm{kPa}$. At another point downstream, the diameter is $75 \mathrm{~mm}$ and the pressure is $359 \mathrm{kPa}$. What is the value of the friction loss $\left(e_{f}\right)$ between these two points? $\left[c_{p}=1005 \mathrm{~J} /(\mathrm{kg} \mathrm{K})\right]$.