The exit section of a convergent-divergent nozzle is to be used for the test section of a supersonic wind tunnel. If the absolute pressure in the test section is to be \(140 \mathrm{kPa}\), what pressure is required in the reservoir to produce a Mach number of 5 in the test section? For the air temperature to be \(-20^{\circ} \mathrm{C}\) in the test section, what temperature is required in the reservoir? What ratio of throat area to test section area is required to meet these conditions?