OK, on the assumption that this is not another tiresome windup, I'll field some of these. Answers in bold.
Okay I saw hurling for the first time a little while ago and I have some questions:
Is there a rule against challenging for the ball while it's on an opponent's stick?
I saw a player carrying the ball on his stick as I know he's required to do according to the rules. He was being followed closely and I thought, all the opponent has to do is to tap the ball carrier's stick with his own stick and the ball will fall to the ground.
There is no rule against challenging for the ball on his hurl as long as you do not make a 'chopping' motion down on to his hurl.
BTW the stick is always called a hurley, right? Why is the ball called a puck? It's not flat so why isn't it a ball?
The stick is a hurley, or hurl. Depends on the part of the country you come from. In Munster it's a hurley, but I always heard it called a hurl in Offaly, Galway etc etc. The ball, however is NOT called a puck. It is called a sliothar, or hurling ball. I think you may be confusing the ball with the action of striking it, which is the 'puck' or 'puc'. (e.g. He pucked the sliothar over the bar).
What's the longest distance a player has struck the ball, er, puck? And what's the longest distance from which a player has scored a point?
There is an annual long Puc contest that takes place over the Cooley mountains in Louth, whereby the object is to cover the distance in as few pucks as possible. I'm not sure there is a record of longest ever, but on a pitch, I saw Jim Troy of Offaly getting a 'wide' against Laois from a puckout from his own goals. It bounced about 10 yards out before scooting wide, so I'd guess it was in flight about 135 metres. As for longest point, again, I'm not sure if it's been recorded, but you'll regularly see good freetakers scoring from up on 100 metres, taking angle into account.
How heavy is the puck? It puzzled me why the backs clear the ball with two hands on the stick, er, hurley. It seemed to me that they could get greater distance with a one-handed tennis-like swing, unless the puck is really heavy.
The puck is not heavy. It is a solid mass however, not air filled like a tennis ball. It's a bit lighter than a baseball, but less dense. A baseball is a decent comparison though. As for one handed vs two handed, no. It's always better to hit it with two hands, like a baseball player or golfer. You generate more power with a long 'stick' with two hands than one, otherwise Tiger Woods would be slapping away with one hand. It's similar to a golf swing, you 'pull' through the ball, rather than pushing like in Tennis. Hence the term 'Pull Hard'.
Hope that helps if you are not another alias being 'funny'. If you are a genuine newbie to hurling, stick with it, you'll love it.