A Steel strip emerges from the hot section of a steel mill at a speed of 20 m/s and a temperature of 1200 K. Its length and thickness are L = 100 m and delta = 0.003 m, respectively, and its density and specific heat are 7900 kg/m^3 and 640 J/kg. K, respectively.

Avccounting for the haet transfer from the top and tghe bottom surfaces and neglecting radiation and strip condution effects, determine the time rate of change of the strip temperature at a distance of 1 m from the leading edage and at the trailing edge. Determine the distance from the leading edge at which the minimum cooling rate is achieved.

When at a point two solid phase changes to one solid phase on cooling then it is known as a) eutectoid point b) eutectic point c) peritectic point d) peritectoid point

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?

Water at the rate of 1 kg/s is forced through a tube with a 2.5 cm inner diameter. the inlet water temperature is 15°c, and the outlet water temperature is 50°c. the tube wall temperature is 14°c higher than the local water temperature all along the length of the tube. what is the length of the tube?