Answer to Question #252964 in Mechanical Engineering for AJA

Question

Expand 2 kg of steam at 15 bar, 320°C, into the wet region to 100°C in a polytropic process where pv^1.21 = C. Determine (a) y2, (b) ΔH, (c) ΔS, (d) nonflow and steady flow work, and (e) Q.

Answer 1

the overall or average increase in temperature ( ΔT) of the concrete roof from the energy absorbed from the sun during a12hour day. Assume that all of the radiation absorbed goes into heating the roof. The specific heat of concrete is about 900 J/kg, and the density is about 2,300 kg/m3.

formula: ΔQ = m c ΔT

answer will: $10.9\degree C$