Sa steel ball with mass =5.21 g is moving horizontally with speed =412 m/s when it strikes a block of hardened steel with mass =14.8 kg (initially at rest). the ball bounces off the block in a perfectly elastic collision. (a) what is the speed of the block immediately after the collision?

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.