Partial solution posted below just unsure how to arrive to it.

3. In the heating system shown below, the thermal resistance of the walls is R. Air of specific heat capacity c is blown in with mass flow from ambient temperature Ta. The thermal capacitance of each chamber is C, and the heat flow from the heater is Qin Qin Ta - To (a) Draw the thermal (electrical) circuit for this system, and label the elements with their impedance. b) Find the total response of the system T,.(s) in terms of Qin(s).Ta(s), and the system variables 3. (a) Not provided