Please help (second law of thermodynamics kind of stuff)

For which pair of objects would adding the same a

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.

In this lab you will use a cart and track to explore various aspects of motion. you will measure and record the time it takes the cart to travel certain distances, and then complete some calculations. in the space below, write a scientific question that you will answer by doing this experiment.