A long horizontal cylinder with a moveable piston is filled with He at $5$ atm and

$25C,$ with a total volume of $50c{m}^3.$ The other side of the piston is in contact with

air at $1$ atm $.$ Once the latch is removed He will expand and eventually the piston

will stop and He reaches the final steady state. The friction between piston and

cylinder wall can be neglected, and He can be assumed ideal gas.

$($a$)$ Calculate work done by He in the cylinder during the expansion

process, and the change of internal energy $U$ and entropy $S$ for He in

the cylinder between the final $($state $2)$ and initial state $($state $1)$

$($b$)$ After the end of the expansion $($state $2),$ you would like to push the

piston slowly back to its original position $($state $3).$ Calculate the

change of $U$ and $S$ of He $,$ and work $W$ done by you between state $2$

and state $3?$

$($c$)$ Comment on the reversibility of the above two processes

please solve on a paper so its easy to comprehend