hai lớp 7A và 7B đi lao động trồng cây. Biết rằng tỉ số giữa số cây trồng được cuarlopws 7A và 7B là 0,8 và lớp 7B trồng nhiều hơn lớp 7A là 20 cây. Tính số cây lớp đã trồng

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.

Asingle-geared blanking press has a stroke of 200 mm and a rated capacity of 320 kn. a cam driven ram is assumed to be capable of delivering the full press load at constant force during the last 15 percent of a constant-velocity stroke. the camshaft has an average speed of 90 rev/min and is geared to the flywheel shaft at a 6: 1 ratio. the total work done is to include an allowance of 16 percent for friction a) estimate the maximum energy fluctuation b) find the rim weight for an effective diameter of 1.2 m and a coefficient of speed fluctuation of 0.10

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?