Consider a gas (non ideal gas) in a piston-cylinder device. This gas undergoes p

Question

Consider a gas (non ideal gas) in a piston-cylinder device. This gas undergoes polytropic process PV17 = constant. Pressure is NOT constant during this process. For this process, calculate the amount of work required to bring the gas from an initial state to the final state. At final state, volume of the gas is 0.9 m3. At initial state, volume, pressure and temperature of the gas are 0.7 m3, 400 kPa and 35 degree C, respectively.

Explanation / Answer

work done = -S PdV but PV^1.7 = constant substitute intial conditions . 400*0.7^1.7 (Kpa*m^3) = constant P = constant *V^(-1.7) work done = -S PdV = - S constant *V^(-1.7) dV = -constant S V^(-1.7) dV = -constant* V^(-1.7+1) /(-1.7+1) = constant *V^-0.7 /0.7 V - > 0.7 to 0.9 =400*0.7^1.7 /0.7 * ( 0.9^-0.7 - 0.7^-0.7) = -64.526 Kpa*m^3 = -64.526 KJ (work required is 64.256 KJ)

Related Questions

Navigate

• Browse (All)
• Browse C
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.