When the half-pipe made its debut in 1998 at the Nagano Winter Olympics, the height of the walls were almost half the size of the walls today. They were 11.5 feet in 1998, but in 2014 the walls were 22 feet at the Winter Olympics in Sochi. The height change was desirable because snowboarders need higher walls in order to lessen the centripetal force, the force bringing them to the center, so they can get more air on the jump. The raised walls lessen the centripetal force because of the equation, Fc= m(v2)/r, in which m and v are the mass and velocity of the snowboarder, and r is the height of the walls of the half-pipe.