Answer:
1.04Btu/s from the liquid to the surroundings
Explanation:
Given
m = 2lb/s
V1 = 40.09Btu/lb
V2 = 40.94Btu/lb
z1 = 0ft, z2 = 100ft
g = 32.174 ft/s²
Wc = 3Btu/s
The balance on the pump is given as
Qc - Wc + m[(h1 - h2) + ½(V1² - V2²) + g(z1 - z2) ] = 0
By neglecting kinetic energy; we substitute the above values:
This is as follows;
Qc - (-3) + 2[(40.09 - 40.94) + 32.174(0-100)/(778*32.174)] = 0
Qc + 3 + 2(40.09 - 40.94) + 2 * 32.174(0-100)/(778*32.174) = 0
Qc + 3 - 1.7 - 0.257 = 0
Qc = -1.04Btu/s