Can you please solve the second question, I will write it on the exam paper, can you write a simple solution suitable for it?

It is not allowed to use mobile phone during the exam (including using the calculator function of the phone). All the mobile phones must be given to the Exam executer It is not permitted to talk/to use the other's calculator/to use and reod documents except given or permitted by the 1) (50pts) A well-insulated shell-and-tube heat exchanger is used to heat water (cp= 4.18kJ/kgC ) in the tubes from 20 to 70C at a rate of 4.5kg/s. Heat is supplied by hot oil ( cp =2.30kJ/kgC ) that enters the shell side at 170C at a rate of 10kg/s. Determine a) the time rate of heat transfer in the heat exchanger and b) the exit temperature of oil. (See figure I) Assumptions 1Changes in the kinetic and potential energies of fluid streams are negligible. 2 Fluid properties are constant. 2) (50 pts) Air is contained in a vertical piston-cylinder assembly fitted with an clectrical resistor. The atmosphere exerts a pressure of 1 bar on the top of the piston, which has a mass of 45kg and area of 0,09m2. Electric current passes through the resistor, and the volume of the air slowly increases by 0,045m3 while its pressure remains constant. The mass of the air is 0,27kg, and its specific internal energy increases by 42kJ/kg. The air and piston are at rest initially and finally. The piston cylinder system is well insulated. Friction between the piston and eylinder wall can be ignored, and the local acceleration of gravity is g=9,81m/s2. Determine the electrical work performed by the resistor, in kJ. (See figure 2)