A tennis ball is dropped from 1.17 m above the ground. It rebounds to a height of 0.857 m. With what velocity does it hit the ground? The acceleration of gravity is 9.8 m/s^2. (Letdown be negative.) Answer in units of m/s.

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What is the measure of a change in an objects velocity?

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.