Asteel plate 0.1 meters thick is initially at a uniform temperature of 200 °c. the steel plate is to be annealed in a gas furnace by heating the plate to a minimum temperature of 550 °c. the temperature of the combustion products is 800 °c and the convection coefficient is 250 w/m2*k. both sides of the plate are exposed to the convection heat transfer. determine the time the steel plate should reside in the furnace. (plate: r = 7830 kg/m3; cp = 550 j/kg*k; k = 48 w/m*k)

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?

Agas mixture consists of 8 kmol of h2 and 2 kmol of n2. determine the mass of each gas and the apparent gas constant of the mixture.

Amass-spring-viscous damper system of mass 3 kg has a frequency of 100 rad/s and is critically damped. its initial conditions are x(0)-3 mm and (0)-2.3 m/s. does the system overshoot its equilibrium position? prove your answer