Nice! I like that you drew in the finger holes on the ball. People in my class tried to get around that by just saying they were animating some type of generic heavy ball.
The fall seems rather slow, in my honest opinion. It looks like it's floating down rather than landing with a thud. When animating a heavy object, I would recommend only a few frames of it falling to enhance the illusion of it hurtling towards the floor. Otherwise, very nice!