Question 4 2 pts
A roller coaster car (includes mass of occupants) is passing through a vertical loop.
The radius of curvature of the loop is 39 m. What would the minimum speed have to
be to make it around the loop safely?
v2
= gr

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.