Asolid steel sphere (aisi 1010), 300 mm in diameter, is coated with a dielectric material layer of thickness 2 mm and thermal conductivity 0.04 w/m middot k. the coated sphere is initially at a uniform temperature of 500degreec and is suddenly quenched in a large oil bath for which tinfinity = 100degreec and h = 3300 w/m2 middot k estimate the time required for the coated sphere temperature to reach 140degreec. hint: neglect the effect of energy storage in the dielectric material, since its thermal capacitance (pcv) is small compared to that of the steel sphere.

Manometers are good examples of measuring instruments, nowadays they are not as common as before. a)-capacitive probe gauges b)-gravitational gauges deformation ) gauges d)-digital gauges

Apiston-cylinder device contains 0.1 m3 of liquid water and 0.9 m3 of water vapor in equilibrium at 800 kpa. heat is transferred at constant pressure until the temperature of water reaches 350 °c. determine (a) the quality of water at the initial state (b) the work associated with this process, (c) the heat associated with this process.

Liquid flows at steady state at a rate of 2 lb/'s through a pump, which operates to raise the elevation of the liquid 100 ft from control volume inlet to exit. the liquid specific enthalpy at the inlet is 40.09 btu/lb and at the exit is 40.94 btub. the pump requires 3 btu/s of power to operate. if kinetic energy effects are negligible and gravitational acceleration is 32.174 tt/s, the heat transfer rate associated with this steady state process is most closely 1)-2,02 btu/s from the liquid to the surroundings 2)-3.98 btu/s from the surroundings to the liquid. 3)-4.96 btu/s from the surroundings to the liquid. 4)-1.04 btu/s from the liquid to the surroundings.