Asag vertical curve connects a -1.5%grade and a +1.5% grade on a
freight and intercity main linerailway track. if the grades
intersect at station (300+25.35)and an elevation of 350.50ft,
determine the stations and elevationsof the bvc and evc and the
elevations on the curve at 100-ftintervals.

Explain the difference laminar and turbulent flow. explain it with the shear stress and the velocity profiles.

On a average work day more than work place firs are reorted

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?