Engineering, 16.10.2020 14:01 Sparkleskeepsgoing

A small, un-insulated closed cylinder with a freely moving piston contains air and is accidentally dropped into a lake and falls slowly to the bottom at 100 m below the surface. Initially, the air in the cylinder is at atmospheric pressure of 100 kPa with a volume of 0.1 m^3and a temperature of 20°C. The lake is also at a uniform and constant temperature of 20C. As the cylinder falls, the air is compressed and there is a heat transfer for the air so that its temperature remains nearly constant at 20°C. Since air can be treated as an ideal gas this implies that the product of pressure and volume is constant (PV = constant) during the process. Neglect the mass of the piston, friction, air leakage from the cylinder, potential energy and kinetic energy effects for the air and determine the following:

a. Final pressure (kPa) of the air at the lake bottom.
b. Final volume (m) of the air at the lake bottom.
c. Work done (kJ) by the air in the device for entire process.

Answers: 3

Show answers

Another question on Engineering

Engineering, 04.07.2019 18:20

Asimple rankine cycle uses water as the working fluid. the water enters the turbine at 10 mpa and 480c while the condenser operates at 6 kpa. if the turbine has an isentropic efficiency of 80 percent while the pump has an isentropic efficiency of 70 percent determine the thermal efficiency

Answers: 1

Answer

Engineering, 04.07.2019 18:20

Amixture of slurry and mud is to be pumped through a horizontal pipe of diameter 500 mm. the fluid behaves as a bingham plastic with a yield stress of 30 pa and viscosity 0.04 pa.s. describe the effects of the shear stress through a transverse section of the pipe by plotting the variation in shear stress and velocity profile: (i) just before the slurry starts to move (ii) as the slurry flows when the pressure gradient is double that in part (i)

Answers: 3

Answer

Engineering, 04.07.2019 19:20

At steady state, air at 200 kpa, 325 k, and mass flow rate of 0.5 kg/s enters an insulated duct having differing inlet and exit cross-sectional areas. the inlet cross-sectional area is 6 cm2. at the duct exit, the pressure of the air is 100 kpa and the velocity is 250 m/s. neglecting potential energy effects and modeling air as an 1.008 kj/kg k, determine ideal gas with constant cp = (a) the velocity of the air at the inlet, in m/s. (b) the temperature of the air at the exit, in k. (c) the exit cross-sectional area, in cm2

Answers: 2

Answer

Engineering, 04.07.2019 19:20

Air enters a horizontal, constant-diameter heating duct operating at steady state at 290 k, 1 bar, with a volumetric flow rate of 0.25 m°/s, and exits at 325 k, 0.95 bar. the flow area is 0.04 m2. assuming the ideal gas model with k = 1.4 for the air, determine (a) the velocity at the inlet and exit, each in m/s, and (c) the rate of heat transfer, in kw flow rate, in kg/s, (b) the mass kg 0.3

Answers: 2

Answer

You know the right answer?

A small, un-insulated closed cylinder with a freely moving piston contains air and is accidentally d...

Questions