Suppose that 30 g of highly compressed air ( C v = 0.177 cal g − 1 C ∘− 1 ) is confined to a cylinder by a piston. Its volume is 2400 c m 3 , its pressure is 10 × 1 0 5 Pa and its temperature is 3 5

Question

Suppose that 30 g of highly compressed air ( C v ​ = 0.177 cal g − 1 C ∘− 1 ) is confined to a cylinder by a piston. Its volume is 2400 c m 3 , its pressure is 10 × 1 0 5 Pa and its temperature is 3 5 ∘ C. The air is expanded adiabatically until its volume is 24,000 c m 3 . During the process 4100 J of work is done by the air. What is its final temperature?

TestHub · Accepted Answer

Adiabatic: Δ U = − W = − 4100 J. m c v ​ = 30 × 0.177 = 5.31 cal K − 1 = 22.2 J K − 1 (1 cal = 4.18 J). Δ T = − 22.2 4100 ​ = − 184.7 K. T f ​ = 308 − 184.7 = 123 K = − 15 0 ∘ C.

Physics - Heat & Thermo Question with Solution | TestHub

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