However, this force acts on the feet, which are far from the center of gravity (r > 0, a torque is produced. In this case, the torque produces a forward angular acceleration that tends to cause the jumper to fall face down into the sand.
Athletes use a few different techniques to counter this rotation. Lean back When you jump, your center of gravity moves closer to where your feet touch the ground, which reduces torque, but it also reduces your speed. Hanging TechniqueA jumper stretches his arms and legs out into the air like a giant sail, and as we’ve seen, this increases the moment of inertia, but probably also creates some extra wind resistance.
The method most Olympic athletes use is Hitch Kick (Carl Lewis, who won four gold medals in this sport, is featured here.) The jumper looks like he is running through the air, “windmilling” his arms and legs as he takes off. This translates the rotation of the body into the rotation of the arms and legs (technically a form of conservation of angular momentum). It is often thought that this running motion makes the jumper fly farther, but this is not the case. With traditional techniques, like the ball model above, the distance is pretty much set once you take off as you fight the spin and make a successful landing.
Somersault Jump
Tuariki Delamere’s approach was radically different. Rather than resisting the rotation, he went with the flow. use That rotation? When it tilts forward Kicking off with his hind legs, moreover It increases your torque and maybe your jump power too, after which you can keep spinning until you hopefully land.
But wait! There’s another benefit: when a jumper draws their knees in towards their chest, they increase their angular velocity (like the ice skater above). This also reduces their cross-sectional area in flight, which reduces air resistance. The effect is small, but remember: small differences can win you gold medals.
The flip long jump has another great advantage: as the athlete rotates through the air, their body is in a bent position and their foot quickly moves forward to make contact with the ground. in front If done correctly, you will roll forward without falling onto your seat or hands.
Delamere’s technique could have led to significant distances in the long jump; many experts believe he could have broken the 30-foot record. (The world record is 29 feet, 4 inches.) But he was never given the chance because sports authorities said it was too dangerous. Apparently, they had never seen gymnastics or ski jumping.
My take? The old guard of athletics is steeped in tradition and has no time for brazen flamboyance or originality, especially when it comes to breaking hallowed records. Maybe that will change. Who knows? After all, breakdancing is now an Olympic sport!
