Answer to Question #115781 in Mechanical Engineering for Smith

Question

During the unidentified process with air, the temperature decreases from 600 0F to 200 0F. Find a. ) the change of internal energy, b.) the change of enthalpy.

Answer 1

$T_1= 600 ^oF, T_2= 200 ^o F$

Internal Energy = nCvdT= $0.1\times 0.17128 \times (200-600)= -68.512 (BTU)$

for enthalpy of air we can use below formula for finding

$dH=n CpdT=0.1\times 0.24\times (-400)= - 96$ BTU