Figure (a) shows a cylinder containing gas and closed by a movable piston. The cylinder is kept submerged in an ice water mixture. 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 (b) is a p-V diagram for the process. If 130 g of ice is melted during the cycle, how much work has been done on the gas?