A tank initially contains 250 gallons of fresh water. Water containing 9 grams of salt per gallon enters the tank at the rate of 10 gallons per minute, and the well mixed solution leaves the tank at the rate of 5 gallons per minute. The amount of salt in the tank after 6 minutes is a) 487.74 grams. b) 511.07 grams. c) 508.86 grams. d) 480.09 grams.

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.

Coiled springs ought to be very strong and stiff. si3n4 is a strong, stiff material. would you select this material for a spring? explain.

During a steady flow process, the change of energy with respect to time is zero. a)- true b)- false