High Jump Physics VIDEO Shows Why Athlete's Center Of Mass Is Key

What does it take for a high jumper to clear the bar? An incredible combination of speed, strength, and technique.

And what ties together those elements? Physics.

Just check out ESPN's "Sport Science" segment above with host John Brenkus and USA Track & Field Jesse Williams, who can clear a bar set 21 inches above his own six-foot height.

Like most jumpers, Williams uses the Fosbury flop, a head-first, backward jumping technique named after legendary Olympic gold medalist Dick Fosbury. What's so special about the flop? It keeps the jumper's center of mass below the bar as the body soars over it -- reducing the amount of energy it takes for a successful jump.

"This phenomenon occurs because his back is arched," Brenkus says about Williams in the video, "placing his center of mass technically outside his body."