Hi, I was learning about collisions, and I stumbled upon this materials, which is interesting because a guy who wrote it gave this interesting example. He was talking about "somewhat inelastic collisions", as he calls them, and he gave an example of a ball bouncing of the floor. Here are the snapshots of that part of lecture http://i.imgur.com/OVkS2.png http://i.imgur.com/g6DTC.png This part, when he posed the question intrigued me the most. It reminded me of Zeno's paradox, which I never quite understood. The way I'm seeing it, as far as the thing about distance goes, mathematically speaking, the ball should bounce less and less, so the total distance traveled converges to some final value (but mind you, it should never reach that value, only gradually become closer and closer to it). Now, as far as the thing about time goes, I am completely baffled by it, I cannot make myself understand it. Again, mathematically speaking, the formula for total time converges to some value. That should mean that the total time will become closer and closer to that value but it should never reach it. This is the logic I picked while learning integrals and derivatives and the limit process behind them. In an example he gave, that time was 1.36 seconds. But we all know that those 1.36 seconds must and will pass, so we will reach this total time value. And when it does, the ball will come to rest, which essentially means that it did reached the total distance value. So clearly, my thought process is wrong. How is it possible then for the ball to bounce infinitely many times? Maybe someone can shed some light on my troubled mind? Much obliged.