(30 points) A constant volume tank filled with 2 kg of air rejects heat to a heat reservoir at 300 K. During the process the temperature of the air in the tank decreases to the reservoir temperature. Determine the expressions for the entropy changes for the tank and reservoir and the total entropy change or entropy generated of this isolated system. Plot these entropy changes (kJ/K vs K coordinates) as functions of the initial temperature of the air. Comment on your results. Assume constant specific heats for air at 300 K. The plot must be computer generated.

The temperature of air decreases as it is compressed by an adiabatic compressor. a)- true b)- false

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.

The thermal expansion or contraction of a given metal is a function of the f a)-density b)-initial temperature c)- temperature difference d)- linear coefficient of thermal expansion e)- final temperature f)- original length