ASSIGNMENT

Engineering thermodynamics

A piston/cylinder contains carbon dioxide at 300 kPa, 100°C with a volume of 0.2 m^3. Weights are added at such a rate that the gas compresses according to the relation PV^1.2 = constant to a final temperature of 200°C. Find the work done during the process.

A cylinder/piston contains 1kg methane gas at 100 kPa, 20°C. The gas is compressed reversibly to a pressure of 800 kPa. What is the work required if the process is isothermal?

At 15°C, a steel pot with a 5 mm thick bottom is filled with liquid water . The pot has a 10 cm radius and is now placed on a stove with a heat transmission of 250 W. Calculate the temperature on the bottom of the outer pot assuming the inner surface is 15°C.

A refrigerator with a 2 kW motor for powering the compressor gives 6000 kJ of cooling to the refrigerated space during 30 minutes of operation in a thermally insulated kitchen. Calculate the change in internal energy of the kitchen if the condenser coil behind the refrigerator rejects 8000 kJ of heat to the kitchen over the same time period.

When the diver is 8 meters below the surface, the pressure gauge on his air tank reads 60 kPa. The gauge pressure will be 0 at what depth?

At 100°C, a sealed rigid vessel with a volume of 1 m3 and 2 kg of water has a volume of 1 m3. The vessel has now been warmed up. What pressure should a safety pressure valve be adjusted to achieve a maximum temperature of 200°C if one is installed?

If a piston/cylinder with a cross-sectional size of 0.01 m2 is resting on the stops, what should the water pressure be to lift the piston with an outside pressure of 100 kPa?