Calculate the surface temperature of a black surface, 1.6 m^2 in area if the rate of heat transfer is 632 kw. the stefan-boltzmann constant is σ = 5.67 x 10^-8 w/m^2 k^4 a) 1734 °c b) 273 °c c) 1625 k d) 1640 k e) 1682 k

Water vapor initially at 10 bar and 400 °c is contained within a piston-cylinder assembly. the water lost heat to the surrounding according to isochoric (iso-volumetric) process until its temperature is 150 °c. the water is then condensed isothermally to saturated liquid. for the water as a system, calculate the work in kj/kg