The hidden forces behind winter sports

Long before he earned the nickname the "Quad God," U.S. men's figure skating champion and gold medalist Ilia Malinin was part of a University of Delaware biomechanics study that measured jumping ability and motion, part of a broader effort to understand how forces, speed and body mechanics impact an athlete's performance.

Now when Malinin launches himself into the air to do a quadruple axel - four and a half rotations - he's not only making history as the only skater in the world to consistently land the jump, he's putting his knowledge of that science to work.

All of the sports at the Winter Olympics in Milano Cortino involve some physics in action. For figure skating, ski jumping and curling, two of the basic laws of the physics of motion are at play: Gravity governs motion, and friction resists it.