10 kg piece of aluminum, initially at 300 k, is melted and used in the casting process. the heating and melting process is divided into two steps. in the first step the piece of aluminum is heated by hot air at 400˚c until its temperature rises to 600 k. then in the second step its temperature increases to 900 k by heating by hot exhaust gas at 1400 k. find the entropy generated in this process. properties of aluminum are the following: density and specific heat of liquid and solid phase: 2700 kg/m3 and 1040 j/kg, latent heat of fusion 321 kj/kg and melting temperature 883 k.

When using the ohmmeter function of a digital multimeter, the leads are placed in what position relative to the component being tested? a. parallel b. control c. series d. line

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?

The drive force for diffusion is 7 fick's first law can be used to solve the non-steady state diffusion. a)-true b)-false