A tree in the way

One day, a grandpa and his grandson go golfing. The young one is really good and the old one is just giving him tips. They are on hole 8 and there is a tree in the way and the grandpa says, "When I was your age, I would hit the ball right over that tree." So, the grandson hits the ball and it bumps against the tree and lands not to far from where it started. "Of course," added the grandpa, "when I was your age, the tree was only 3 feet tall."