Air is contained in a piston-cylinder device at 600 kPa and 927°C, and occupies a volume of 0.8 m. The air undergoes and isothermal (constant temperature) process until the pressure in reduced to 300 kPa. The piston is now fixed in place and not allowed to move while a heat transfer process takes place until the air reaches 27°C. a. ) Sketch the system showing the energies crossing the boundary and the diagram for the combined processes. b ) For the combined processes determine the net amount of heat transfer, in kJ, and its direction. Assume air has constant specific heats evaluated at 300 K.

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.

What is the heat treatment of metals? what is the benefit of it? why and how it's useful? answer in details, do not write by hand.

The characteristic roots of a dynamic system are: 1.7920 1.8160 i, -1.7920 1.8160 i, -0.4160 what is the order of this system? what are the settling time and damping ratio of the system?