GATE Mechanical Engineering (ME) 2020 Shift 2 Solved Paper

Considering Air inside the cylinder as the system
Total work by gas = work done by the spring + work done by weight of piston + Work done by atmosphere
Work done by spring =‌

1

2

k(x22−x12)
=‌

1

2

×12.5×103×(0.08)2
=40J
Work done by atmosphere = Patm × volume
=100×103×0.03×0.16
=480J
Work done by weight of piston:
At initial state
P‌initial ‌× Area =P‌atm ‌× Area +W‌piston ‌
105×103=100×103+‌

W‌piston ‌

0.03

W‌piston ‌=150N
Work done by piston (W‌piston ‌)=150×0.16=24 Joule
So Total work done by gas =40+480+24
=544 Joule