A turbojet engine has a converging nozzle with variable area. At one sea level operating condition, the engine exhaust flow is 100 kg/s and the stagnation state entering the nozzle is 1100K and 3 atm. The specific heat ratio may be assumed constant at 1.33. If the nozzle is isentropic, find the required exit area. If instead the nozzle efficiency is 90%, find the exit stagnation pressure and the percentage increase in required exit area.

Aloaded platform of total mass 500 kg is supported by a dashpot and by a set of springs of effective stiffness 72 kn/m. it is observed that when the platform is depressed through a distance x = 12.5 cm below its equilibrium position and then released without any initial velocity; it reaches its equilibrium position in the shortest possible time without overshoot. find the position and velocity of the loaded platform 0.10 sec. after its release. if a further load of 400 kg is added to the platform, find, i) the frequency of damped vibrations, and i) the amplitude of vibration after 2 complete oscillations, given that the initial amplitude is 15 cm.

Aflywheel accelerates for 5 seconds at 2 rad/s2 from a speed of 20 rpm. determine the total number of revolutions of the flywheel during the period of its acceleration. a.5.65 b.8.43 c. 723 d.6.86

The higher the astm grain size number, the finer the gran is. a)-true b)-false