All articles from: May, 2009

Karate Motion Efficiency Analysis

karate-motion-efficiency-analysis

In this article I would like to describe the proposed title in view of the science of physics. The article will always give examples using 2 martial artists in action. When we deal with 2 martial artists for motion efficiency analysis (KMEA) we have several physical properties to deal with, such as: Force, momentum, impulse, torque, displacement, power, energy, work, mass, inertia, velocity, lever and so on.

In order to describe and categorize the KMEA, I will start with some basic definitions. One of the most important physical property is the force of a human being which is measured by the mass of the participant and multiplied by the acceleration of force (F = ma) or kg(m/sec2). The force is measured in Newton. 1 Newton (N) = 1 kgm/sec2).

Newton 2nd law of acceleration which states that when a body is acted on by a force, its resulting a change in momentum which takes place in the direction in which the force is applied, and is proportional to the force causing it, and inversely proportional to its mass. Change in velocity means acceleration or deceleration by a force which was applied.

In this case we are talking about a new physical property which is the momentum. The momentum (p) = mass x velocity or kgm/sec where m/sec represent velocity in case of linear motion. In case of rotary motion the equation is: L = Iω or I = kgm2/s and ω = rad/sec or (θ/sec). Where the “L” represents the angular momentum, the “I” represents the moment of inertia (angular inertia) the “ω” represents the angular velocity, “m” represents meter and “rad” represents radian, “θ” represents angle of a circle. The momentum represents the amount of motion possessed by a moving body. Thus, a body’s momentum can be changed by altering either its mass or its velocity.

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