Volume Work Calculation of volume Work(i.e. Expansion work, Compression work) Case 1: Expansion or Compression under a constant external pressure, Pex Initial height: Final height Piston movement:△L F F L2 W-F: AL;(Force Distance) F A W=P·A·△L Bottom Surface area=A W=P·△VVolume Work  Calculation of Volume Work (i.e. Expansion work, Compression work)  Case 1: Expansion or Compression under a constant external pressure, Pex) 11 Initial height： L1 Final height： L2 Piston movement： L W = F · L; (Force ·Distance） F = Pex·A W = Pex ·A · L Bottom Surface Area = A W = Pex· V