Question

A piston cylinder contains air at 300 kPa, 310 K and a volume of 0.03$m^3.$ A constant pressure process gives 54 kJ of work out. What is the final temperature of the air?

• A. 1860 K
• B. 2430 K
• C. 2170 K
• D. 2900 K

Answer 1

The correct option is C 2170 K

$W=\int PdV=P\Delta V[\therefore \text{P is constant}]$

$\Delta V=\frac{W}{P}=\frac{54}{300}=0.18m^3$

$V_2=V_1+\Delta V=0.03+0.18=0.21m^3$

Using ideal gas equation

$[P_1=P_2]$

$T_2=\frac{V_2}{V_1}\times T_1=\frac{0.21}{0.03}\times 310=2170K$