I made a couple of attempts at a bouncing ball and a sliding ball. For the first one, I tried to recreate the bounce of a ping pong ball and for the sliding one, my reference was a bowling ball.
I felt I could understand the dynamic of the bowling ball better compared to the ping pong one. For the latter, I found it quite hard to get the arcs right. Also, before approaching the exercise I thought there would be more squash and stretch involved into the animation, but after the first try, I realised it made it look quite odd, so I refrained from using too many of those frames.