For high-speed motion through the air - such as the skydiver falling before the parachute is opened - air resistance is closer to a power of the instantaneous velocity v(t)v(t). Determine a differential equation for the velocity v(t)v(t) of a falling body of mass mm if air resistance is proportional to the square of the instantaneous velocity.

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.

Apressure vessel with an r/t 20 cannot be treated as thin walled vessel. a)-trune b)- false

Determine (a) the maximum thermal efficiency of reversible power cycles operating between a hot reservoir at 1000°c and a cold reservoir at 200°c and (b) the maximum cops for reversible refrigeration and heat pump cycies, respectively, between 28°c and 14°c.