You can try to describe this type of trick till you’re blue in the face but it takes an actual physicist like the author of Gold Medal Physics: The Science of Sports, John Eric Goff, to enlighten us to the forces at work when a snowboarder miraculously pulls four off-axis flips and five full spins and somehow lands on their feet.
Big thanks to WIRED and Mr. Goff for breaking down one of the sickest tricks ever landed on a snowboard (Follow Billy Morgan HERE). Share this with anyone that you need to get hyped on snowboarding before the Olympics:
Olympic boarders will accelerate down 240 feet of slope, 39 degrees at its steepest, before hurtling off the ramp. Speed is key here: Too slow, and they won’t get enough air to complete four flips. Goff estimates Morgan hits approximately 40 mph at takeoff.
2 Initiate Spin
Achieving the quad cork’s tricky combination of flip and spin requires a simultaneous trunk twist and abdominal crunch. That quick movement likely generates about 50 foot-pounds of torque, 1,000 times the torque it takes to turn your head.
3 Optimize Posture
As his body spirals through the air, Morgan crouches and grabs his board. The smaller he can tuck—minimizing the moment of inertia—the faster he rotates. During the first cork, he throws his left arm out to the side to adjust his rotational direction.
4 Achieve Speed
Morgan pulls both of his arms into his chest like a twirling figure skater to pick up the pace. He needs to spin as quickly as possible to complete all five rotations before touchdown, averaging a whiplash-inducing 1.7 revolutions per second.
5 Brace for Impact
As he completes the last cork, Morgan throws out his arms and straightens his body to slow the rotation. He hits the ground going approximately 50 mph with about 450 pounds of force on each leg, Goff says, about half the force it takes to fracture a bone.
6 Stick It
Morgan lands with his board at a 14-degree angle to decelerate gradually. He bends his knees as he touches down, which extends his collision time and distributes the force. All told, he executes the trick in 2.9 seconds of hang time, soaring 133 feet over the snow.