Question

9. Tennis ball is dropped on the floor from a height of 100m. it rebounds to
height of 100m. if the ball was in contact with the floor for 13.6 sec. then the
average acceleration during the contact is
a) 700m/s? b) 140m/s? c) 280 m/s2 d) 28m/s2​

Answer 1

28 the answer is D

And this is whole process