wo frictionless carts are on a horizontal track. The first cart is initially at rest, and has a mass of 0.500 kg. It has a massless spring for a bumper (with spring constant 400 N/m). The second cart (mass of 0.800 kg), heads towards it from the left with a velocity of 2.00 m/s. a) What speed do the two carts have when they are travelling at the same speed

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.