1. 25 kg min of oil is heated as it flows through a thick wall copper pipe connected to the electrical power supply. The external wall of the pipe is perfectly insulated and the temperature of the inner wall is constant. (a) (b) Give a physical interpretation and show the units of the following terms in Eq 1: (i) pcp (ii) PCpVr ar (iii) k- 1 0 r2 002 Simplify the energy balance for the oil justifying all the assumptions and write appropriate boundary conditions. Do not attempt to solve the resulting equation. [20%] Assume that the pipe is very long and simplify the energy balance for the pipe justifying all simplifications. Solve the resulting differential equation using appropriate boundary conditions to obtain the radial temperature distribution in the pipe wall. Data: Eq. 1 PCp+Vr ve + + V =k + 1 aT aT] +S