A gas enters a nozzle steadily at 2.21 kg/m3 and 30 m/s and leaves at 0.762 kg/m3 and 180 m/s. The area of the inlet of the nozzle is 80 cm2 . Find (a) the mass flow rate through the nozzle, and (b) the area of the exit of the nozzle.

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.