Ahorizontal cylinder 10 cm in diameter contains helium gas at room temperature and atmospheric pressure. A piston keeps
the gas inside a region of the cylinder 20 cm long.
(a) If you quickly pull the piston outward a distance of 12 cm, what is the approximate temperature of the helium
immediately afterward? What approximations did you make?
(b) How much work did you do, including sign? (Note that you need to consider the outside air as well as the inside
helium in calculating the amount of work you do.)
(c) Immediately after the pull, what force must you exert on the piston to hold it in position (with the helium enclosed
in a volume that is 20 + 12 = 32 cm long)?
(d) You wait while the helium slowly returns to room temperature, maintaining the piston at its current location. After
this wait, what force must you exert to hold the piston in position?
(e) Next, you very slowly allow the piston to move back into the cylinder, stopping when the region of helium gas is 25
cm long. What force must you exert to hold the piston at this position? What approximations did you make?