Question

fifty btu are added to one pound of air during a constant pressure process starting at a temperature of 100°F. Calculate the final temperature of the air, degrees F, for a constant pressure specific heat of 0.24 BTU/lb-°F. The calculate the final temperature of the air, starting at 100°F, for the same quantity of heat added during a constant volume process for which the average specific heat is 0.171 BTU/lb-°F

Answer 1

1)

$$Q=mc_p(T_1-T)$$

$$50=(1)(0.24)(T_1-100)$$

$$T_1=308\degree F$$

2)

$$Q=mc_v(T_2-T)$$

$$50=(1)(0.171)(T_2-100)$$

$$T_2=392\degree F$$