An uncold-worked brass specimen of average grain size 0.008 mm has a yield strength of 160 mpa (23,500 psi). estimate the yield strength of this alloy after it has been heated to 600°c for 1000 s and has achieved grain size of 0.20 mm, if it is known that the value of ky is 12.0 mpa-mm1/2 (1740 psi-mm1/2).

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.

Fluids at rest possess no flow energy. a)- true b)- false

Determine whether or not it is possible to compress air adiabatically from k to 140 kpa and 400 k. what is the entropy change during this process?