The radiator of a steam heating system has a volume of 20 L and is filled with superheated water vapor at 200 kPa and 150oC. At this moment, both the inlet and the exit valves to the radiator are closed. After a while, the temperature of the steam drops to 40oC as a result of heat transfer to the room air. Determine the entropy change of the steam during this process

Apiston-cylinder with a volume of 0.25 m3 holds 1 kg of air (r 0.287 k/kgk) at a temperature of 100 c. heat transfer to the cylinder causes an isothermal expansion of the piston until the volume triples. how much heat is added to the piston-cylinder?

The higher the astm grain-size number, the coarser the grain is. a)-true b)-false

Consider a large isothermal enclosure that is maintained at a uniform temperature of 2000 k. calculate the emissive power of the radiation that emerges from a small aperture on the enclosure surface. what is the wavelength ? , below which 10% of the emission is concentrated? what is the wavelength ? 2 above which 10% of the emission is concentrated? determine the wavelength at which maximum spectral emissive power occurs. what is the irradiation incident on a small object placed inside the enclosure?