Q2: A spherical vessel of 0.9 m³ capacity contains steam at 8 bar and 0.9 dryness fraction as shown in Figure 1. The steam is blown off through a valve until the pressure drops to 4 bar. The valve is then closed, and the steam is allowed to cool until the pressure falls to 3bar. Assuming that the enthalpy of the steam in the vessel remains constant during blowing off periods, determine: (1) The mass of the steam blown off cooling (find the dryness fraction or the degree of superheated depending on the condition) (2) The condition of the steam in the vessel after

Re= 77419.2

The atmospheric lapse rate on a particular day is constant in the lower part of the atmosphere. At ground level, the pressure is 1020 mBar and the temperature is 15°C. At a height z1 the pressure and temperature are 975 mBar and 11.5 °C. Determine the atmospheric temperature gradient, and the height z1.  

5. Solar ponds are small artificial lakes used to store solar energy. The rise of heated (and thus less dense) water to the surface is prevented by adding salt at the pond bottom. In a typical salt gradient solar pond, the density of water increases in the gradient zone, as shown. For H 4 m, po 1040 kg/m³, and a thickness of 0.8 m for the surface zone, calculate the gauge pressure at the bottom of the gradient zone. V S Sun = = H=4m = Surface zone Po 1040 kg/m³ Increasing salinity and density Gradient zone Storage zone - (2 Po=1040 kg/m P= Po(1+35+5²)

When two objects at different temperatures are brought into contact with one another (such as a hot steel bar dropped into cold water), the cold object will O increase in temperature to the same temperature as the hot object before being placed in the water. O lose as much heat as the hot object loses the cold object will remain unchanged O gain as much heat as the hot object loses

Two hundred kJ of work is transferred to the air by means of a paddle wheel inserted into an insulated volume . If the initial pressure and temperature are 200 kPa and 100 °C, respectively, determine the final temperature and pressure.

Determine the efficiency for the cycle (standard air used as the working fluid) indicated in the sketch. Assume the pressures and temperatures are known quantities at each state. 1-2 constant volume process and 2-3 constant pressure process.

May I ask if a block of copper falling into a tank filled with water is considered a closed or open steady system?

On a day when wind is blowing over a lake (T(water) =20°C) at 5 m/s, which side of the air-water interface will be rate-limiting on the flux of Ethyl benzene (i.e. va or vw)?

4. A mass of 1.7 kg of saturated liquid water is completely vaporized at a constant pressure of 101.325 kPa. Determine (a) the volume change and (b) the amount of energy transferred to the water.