Aconverging-diverging nozzle is designed to produce a mach number of 2.5 with air. a) what operating pressure ratio (preceiver/ptotal) will cause this nozzle to operate at the first, second, and third critical points? b) if the inlet stagnation pressure is 150 psia, what receiver pressures that represent the operation at these three critical points?

Ariver flows from north to south at 8 km/h. a boat is to cross this river from west to east at a speed of 20 km/h (speed of the boat with respect to the earth/ground). at what angle (in degrees) must the boat be pointed upstream such that it will proceed directly across the river (hint: find the speed of the boat with respect to water/river)? a 288 b. 21.8 c. 326 d. 30.2