Figure 18-55a shows a cylinder containing gas and closed by a

movable piston. The cylinder is kept submerged in an ice – water mix-

ture. The piston is quickly pushed down from position 1 to position 2

and then held at position 2 until the gas is again at the temperature of

the ice – water mixture; it then is slowly raised back to position 1.

Figure 18-55bis a p-V diagram for the process. If 100 g of ice is

melted during the cycle, how much work has been done on the gas?