Apiston cylinder device with a set of stops contains steam. initial pressure, temperature, and volume are 400 kpa, 300°c, and 1.5m^2. heat was removed from the system until the temperature of the system reaches 100°c at which the piston is touching the stops and the volume is 0.5m^3. a) show this process on p-v and t-v diagrams. b) determine the change in the internal energy, in kj, from the initial state to the instant the piston hits the stops. c) determine the work done, in kj, during the entire process.

Air is to be cooled in the evaporator section of a refrigerator by passing it over a bank of 0.8-cm-outer-diameter and 0.4-m-long tubes inside which the refrigerant is evaporating at -20°c. air approaches the tube bank in the normal direction at 0°c and 1 atm with a mean velocity of 4 m/s. the tubes are arranged in-line with longitudinal and transverse pitches of sl- st 1.5 cm. there are 30 rows in the flow direction with 15 tubes in each row. determine (a) the refrigeration capacity of this system and (b) pressure drop across the tube bank. evaluate the air properties at an assumed mean temperature of -5°c and 1 atm. is this a good assumption?

During a steady flow process, the change of energy with respect to time is zero. a)- true b)- false

Different types of steels contain different elements that alter the characteristics of the steel. for each of the following elements, explain what the element does when alloyed with steel.