Physics of Karate Essay -- physics martial arts fighting

The basic ideas behind any style of karate can in general be reduced to the goal of achieving the most effective movements with the least effort. Specifically, with a strike such as a punch, kick, knife-hand or similar, the karateka attempts to move smoothly through the strikes, conserving energy towards the impact point. When thought about in terms of energy, the most common equation is that of rotational kinetic energy, or KE=(1/2)mv^2 + (1/2)Iω^2. Another way to think about a strike is to attempt to focus as much force as possible at the point of impact. In many strikes, this is facilitated by drawing an almost straight line with the striking tool from the original point of rest to the point of impact. This is based on the fact that the fastest path between two points is a direct line, and greater speed leads to corresponding greater force upon impact, as shown by Newton's Second Law, F=ma. This equation also leads to the conclusion that if increased mass is used in the strike, the force upon impact will be greater. Because of the obviousness of this idea, most strikes are thrown through the rotation of the body in some way, instead of simply from the arms or legs. The body has much more mass, and therefore contributes greatly to achieving a strike that is highly forceful, yet doesn't require nearly as much effort as one thrown from the extremeties. Front Stance Equations: W=mg ÃŽ ¤=IÃŽ ± ÃŽ ¤=Fr; friction F=ÃŽ ¼N The most basic part of a succesful technique is a proper stance that is well grounded and solid. This helps in many ways, including providing the initial push behind a technique, grounding the karateka during the moment of impact, and providing a solid base from which to defend against an attacker. ... ...rown into the rotation, the more energy is contained in the leg at this stage in the kick. The next stage of the kick switches to upwards and forward rotation of the knee around the hip joint. This is also connected to the equations v=ωr and KE=(1/2)mv^2 + (1/2)Iω^2, thus KE=(1/2)m(ωr)^2 + (1/2)Iω^2. In a properly executed kick, this transition is completely smooth, and energy is conserved. This leads to the idea that a vital part of a proper, focused front kick is how quickly and smoothly the back leg is pulled forward. The last step in the kick is the upwards rotation of the foot around the knee joint, the kinetic energy of which is found through exactly the same equations. To ensure that the energy is expended on forward impact rather than upwards, during the rotation around the knee, the hip should be extended forward slightly just before impact.