During flight only weight and air resistance acts on the performer. AR is negligible for this small amount of time and therefore the CoM follows a path that is very close to a true parabola.
CoM:
at takeoff, reaction force passes behind the jumpers CoM which is an eccentric force that generates angular motion. Therfore during flight there is a tendency to rotate forwards. In order to conteract this rotation the long jumper uses the hang or the hitchkcik.
During flight just before the landing the arms and legs are stretched out in front therefore their CoM moves forwards and lies outside the body. This is beneficial as it minimises the risk of falling backwards into the pit on landing.
Comments
No comments have yet been made