Air with a mass flow rate of 2 kg/s enters a horizontal nozzle operating at steady state at 450K, 350 kPa, and velocity of 3 m/s. At the exit, the temperature is 300 K and the velocity is 460 m/s. Assume air is an ideal gas. (a) Draw a schematic and list all assumptions. (b) Identify if you want to treat air to have a constant specific heat or variable specific heat. Calculate the change in specific enthalpy of air (in kJ/kg) between the nozzle outlet and the inlet based on your assumption. (c) Determine the rate of heat transfer between the nozzle at its surroundings (in kJ/s). Specify whether the heat transfer is to or from the air.

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.