In the thin wall tube-in-tube heat exchanger oil flows in the gap and water flows through the inner tube with walls heated by electrical current at a constant heat flux. The flow of the oil is one-dimensional and can be described by the z component of the momentum balance (Eq. 1). Eq. 2 gives general thermal energy balance for oil. (tvz+vrrvz+rvvz+vzzvz)=zp+[r1r(rrvz)+r2122vz+z22vz]+gztT+vrrT+rvT+vzzT=cpk[r1r(rrT)+r2122T+z22T]+cps (a) Give the physical interpretation of all terms in Eqs 1 and 2. Assuming the heat exchanger is very long, simplify the momentum and the energy balances, justifying all the assumptions. Do not attempt to solve the resulting equations