The art of Karate is not only about its beauty in positions, of his formal acts or his exquisite search for perfection. Art also seeks to guarantee maximum efficiency with the essential effort without the need to waste it in vain.; es decir, the optimal use of our physical and mental conditions for a specific purpose, conduct or technique.
Use this study to analyze this last part, which is directly related to physics.
For this we will connect three concepts present at all times in Karate techniques: space, Mass and Time. This combination properly treated through training, it will improve our Strength and Energy used in each execution.
We will start for clarification, a basic definition of each acting element that will adapt the reader to a better understanding of the study.
- Speed. It is the displacement of an object per unit of time. We represent it through the following formula, where "V" will be the velocity, “E” the space traveled and “t” the time necessary to carry out said movement:
V = e / t
- Acceleration. It is the change in speed per unit of time. In this case "A" will refer to the acceleration.
A = V / t
A = e / t2
- Force. It is the action capable of modifying the movement or shape of an object. The simplified equation that leads us to this definition is the following, where "F" will be the force used to move an object that has a specific "m" or mass.
F = m x A
F = (m x e) / t2
- Kinetic energy. It is the energy that the object possesses as a result of its movement, being the concept energy as the ability to do a job. It is represented by the nomenclature "Ec".
Ec = ½ m x v2
Ec = (0,5 x m x e2) / t2
- Power. It is the amount of force applied to a body in relation to the speed with which it is applied. We will represent it with the letter "P".
P = F x v
P = (m x e2) / t3
Based on the physical formulas raised, we are going to carry out some practical examples where we can observe to what extent each concept interacts according to the value we contribute.
To simplify our study, so that the comparison is easy to understand, We will give a fixed value to the Space that will represent the distance, for example, from when my fist starts the action until it reaches its goal. En este caso, the space will have a fixed value of 1m.
In the same way, we will start the study giving an initial value to the Mass (which represents, for example, the weight of the arm that performs the technique) and the time that elapses from the start of the action to the impact with its objective. These values will be 10 kg and 1 seg. respectively.
Posteriormente, in order to evaluate the different combinations depending on the variability in Mass or Time, we will increase or decrease these parameters in a percentage 10%. This increase or decrease will show the comparative evolution offered by the Force and kinetic Energy developed in the same technical action..
Por tanto, we start the analysis with the following fixed data:
e = 1m t = 1seg m = 10kg
And from this data, we obtain the following results after applying the corresponding formulas:
F = (10 x 1) / 12 = 10 Newtons (Nw)
Ec = (0,5 x 10 x 12) / 12 = 5 Joules (J)
P = (10 x 12) / 13 = 10 Watts (W)
These results will be the comparative basis with the following variations. Remember that we will increase or decrease a 10% the value of Time and Mass.
EXAMPLE 1. Increase 10% Run time (t = 1,1seg)
F = (10 x 1) / 1,12 = 8,26 Nw (-17,36%)
Ec = (0,5 x 10 x 12) / 1,12 = 4,13 J (-17,36%)
P = (10 x 12) / 1,13 = 7,51 W (-24,87%)
EXAMPLE 2. Decrease 10% Run time (t = 0.9seg)
F = (10 x 1) / 0,92 = 12,35 Nw (+23,46%)
Ec = (0,5 x 10 x 12) / 0,92 = 6,17 J (+23,46%)
P = (10 x 12) / 0,93 = 13,72 W (+37,17%)
EXAMPLE 3. Increase 10% body mass (m = 11kg)
F = (11 x 1) / 12 = 11,00 Nw (+10,00%)
Ec = (0,5 x 11 x 12) / 12 = 5,50 J (+10,00%)
P = (11 x 12) / 13 = 11,00 W (+10,00%)
EXAMPLE 4. Decrease 10% body mass (m = 9kg)
F = (9 x 1) / 12 = 9,00 Nw (-10,00%)
Ec = (0,5 x 9 x 12) / 12 = 4,50 J (-10,00%)
P = (9 x 12) / 13 = 9,00 W (-10,00%)
Popular belief, mistakenly tells us that body mass, muscle development or extra kilograms a person can weigh, give you an advantage a priori in Strength, Energy or Power, However, science tells us in EXAMPLE 2, that Time is the crucial factor that tips the balance. The smaller it is, the higher the result obtained, since it acts exponentially in the formulation, while the Mass does it progressively and constantly. We may have heard the quote "A bullet doesn't kill; kills the speed it takes ".
Por este motivo, martial arts seek speed of movement (reduce execution time) before a muscle gain, which is beneficial to the extent that it is not to the detriment of our muscle contraction and expansion.
For a better visualization of the impact that Time has on the Force, Energy and Power, Some evolutionary graphs are attached where you can check the way that Time affects exponentially with respect to Mass.. In this comparative case, the registered data of the Mass is progressively increased in value by one 10% until reaching the 50% of the initial value. In the same way, Time we reduce it gradually in values of the 10% up to a maximum of 50%.
Daniel Tchey Baffioni – 6º dan RFEK