Creating multiple scenes in sequencer?

So I created a scene that involved a car moving, and a ball flying out of it and back into it to demonstrate inertia. I also made a second animation that involved the ball flying up and backwards to demonstrate air resistance. When I went to render them, it ended up showing both the original ball and the new one. I ended up having to delete one of them and the entire keyframe graph I made just so I could render it out.

I want to know, for the future, how can I set up complex animations, that require more than one motion? Thanks.