A gas initially at 1.5 bar pressure, 0.15m

3

volume and 300 K was compressed

polytropically (pv 1.25 = constant) to 15 bar pressure. Determine the change

in entropy. Also work out the approximate entropy change obtained by

dividing the heat transferred by the mean absolute temperature during compression.

Take cp = 1.04 kJ / kg K and cv = 0.745 kJ / kg K.

If you were designing a bumper for a car, would you prefer it to exhibit elastic or plastic deformation? why? consider the functions of a bumper in both a minor "fender-bender" and a major collision.

Two flowing streams of argon gas are adiabatically mixed to form a single flow/stream. one stream is 1.5 kg/s at 400 kpa and 200 c while the second stream is 2kg/s at 500 kpa and 100 ? . it is stated that the exit state of the mixed single flow of argon gas is 150 c and 300 kpa. assuming there is no work output or input during the mixing process, does this process violate either the first or the second law or both? explain and state all your assumptions.

Which of the following is an easy way to remember the modified “x” tire rotation? a. nondrive wheels straight, cross the drive wheels b. drive wheels straight, cross the nondrive wheels c. drive wheels crossed, nondrive wheels straight d. drive wheels crossed, nondrive wheels crossed