what is the answer to questions 20, 21, and 22

020 (part 1 of 3) 10.0 points A tennis ball is dropped from 1.27 m above the ground. It rebounds to a height of 0.921 m. With what velocity does it hit the ground? The acceleration of gravity is 9.8 m/s". (Let down be negative.) Answer in units of m/s. 021 (part 2 of 3) 10.0 points With what velocity does it leave the ground? Answer in units of m/s. 022 (part 3 of 3) 10.0 points If the tennis ball were in contact with the ground for 0.0143 s, find the acceleration given to the tennis ball by the ground