Imagine that you have an infinite amount of dominos(same mass) lined up(at the same distance).

And let's say that the first domino have been pushed with great force(like that of a bullet.)

Now here's the question. What will happen to the toppling speed after a very, very long time?

1. They will still topple with the same speed like the first one.

2. The dominos will slow down until it reaches a constant speed.

3. It would stop toppling at some point.

4. Other answer(please state).

I've worked out mine because I'm applying to Uni, and I've shoved it into my personal statement. I want to make sure I have a reasonable (approximate) answer, so if you fancy working out an approximation of your angular momentum, it would be really useful. 

It's also quite a fun experiment. Don't get too dizzy. 

Is this any different from two non-spinning objects colliding? For example take two spheres (made of eg. wood) x -> 1kg and y -> 2kg spinning with 100rpm and 200rpm respectively. Is there any other factors involved? A way to think about it may be to visualise two spinning tops colliding vs two spheres. By the way, how will friction be involved, and what will happen if this is done in a vacuum?