Which of these requires an increase in power? * Doing half as much work in the same amount of time
Doing the same amount of work in half the time
Doing the same amount of work in twice as much time
Doing twice as much work in twice as much time

Arigid tank is divided into two equal parts by a partition. one part of the tank contains 3 kg of compressed liquid water at 400 kpa and 60°c while the other part is evacuated. the partition is now removed, and the water expands to fill the entire tank. determine the entropy change of water during this process, if the final pressure in the tank is 40 kpa. use steam tables.