1.0 kg of air at 300 k and 100 kpa (state 1) is slowly compressed in a piston cylinder (closed system). the compression process is an isothermal process (t-constant) which is a special polytropic process with a polytropic index n = 1. the pressure of the air at the end of the compression process is 300 kpa (ps). assuming that air is an ideal gas with constant specific heats a)- find the work transfer in this compression process b)-find the heat transfer in this compression process. ignoring the kinetic and potential energy changes c)- find the isentropic efficiency of this compressor

Steel is coated with a thin layer of ceramic to protect against corrosion. what do you expect to happen to the coating when the temperature of the steel is increased significantly? explain.

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.

Thermal stresses are developed in a metal when its a) initial temperature is changed b) final temperature is changed c) density is changed d) thermal deformation is prevented e) expansion is prevented f) contraction is prevented