A static test stand is to be designed for testing a diffuser of a jet engine. The following conditions are known for the test: 50 kg/s of air enter a diffuser at a velocity of 750m/s and static pressure of 20kPa. The air leaves the diffuser at a velocity of 90 m/s and static pressure of 330 kPa. The entrance area of the diffuser is 0.25 m2and the exit area is 0.28 m3. Determine the magnitude and direction of the strut force necessary to hold the diffuser stationary when this diffuser is operated in an atmospheric pressure of 20 kPa.

Acylinder with a movable piston contains 11.7 moles of a monatomic ideal gas at a pressure of 1.32×10^5 pa. the gas is initially at a temperature of 300 k. an electric heater adds 43200 j of energy into the gas while the piston moves in such a way that the pressure remains constant. cp=20.79 j k^−1 mol^−1 for a monatomic ideal gas, and that the number of gas molecules is equal to avogadro's number (6.022×10^23) times the number of moles of the gas. (a) what is the temperature of the gas after the energy is added? (b) what is the change in volume of the gas? (c) how much work is done by the gas during this process?