We already now that this position is a dead draw as long as White keeps his king on a2 and b2, and shuffles his rook along the h-file.
(Yes, since many of us are probably too accustomed to seeing White as the stronger side, I decided to make a change for now)
So now, take a look at the following 3 positions (all Black to move):
And of course the question is: For each of these positions, can Black win, or will it be a draw?
By now this should be quite trivial for many of us, so cracking this puzzle won't take long. Have fun! (: