中国武术寸劲杀伤力的物理学解释
请读者保持耐心，我保证尽可能少的使用物理学名词，公式。而且使用的是基础物理。
我中华拳术，素重速度与力量的短促爆发。这是有物理学根据的。
物理学中，衡量动能为,M为质量，而速度V则以乘方作指数级变动，敏感性与重要性尤大。
如同一颗子弹，质量可说极小，但因速度极快，因而杀伤性极大。
但衡量拳的击打效果，是否就仅仅看动能就行了呢？就是说，只要拳手的质量（一般而言，拳重不应小于拳手体重）够大，速度越快，他的杀伤力就越大呢？
当然不是，因为这应该涉及到冲量的概念。
而古中国武术家们，已经从实践中掌握了这一原理，就如同我们在知道燃烧化学公式之前，已经懂得使用火。
所以心意，形意，通臂，等诸拳，甚至枪械等，明示‘劲’‘力’不同。劲，从力从巠，巠本义为水脉，引为路径，脉理，故劲之本义，即有理法，有路径之力。又劲音同‘进’，训诂学以字之音同，其义每不相远。故劲强调力之‘进入’，‘透入’。要言之，劲字之音形义，已明示其有力之运用方式，法则，门路等因素。
拳到极处，殊途同归，所以我国诸拳法无不强调拳之冲量效果。最明显的要属八极拳。八极发劲要领讲求崩、撼、突击。崩，如山崩之势；撼，如撼震山岳；突击，为用法突然，动作干脆。力贯肩、肘、拳、胯、膝、脚于一体之整，发力瞬间劲如崩弓，发如炸雷。
其它通背、形意等拳术，有譬如‘冷弹脆快’，‘弹抖’，‘身似弓手似箭’，‘扎枪如射箭’等说法。甚至就连‘运柔成刚’的太极，亦有‘松’，‘发功如放箭’之语。举一例，发放飞刀，在施加最初作用力后，即如同给一冲力，其后任其自驶。则其力量与深入程度，大于你用同样力量，手持刀柄所能造成打击效果。
拳王阿里曾经比喻‘出拳要象碰到一块烧红的烙铁’，也是说拳要短促。
其实上述说的都是把冲量最大化。
此外，咏春拳亦以“寸劲”著称，因据传其创始人为女子，力量有限，故短桥窄马，拳出力止。所谓“寸劲”，即短促爆发出的力量。简单说：短促距离，短促时间，爆发性力量。仅就其物理学特征而言，“寸劲”约略当于力学中的“冲力”。
习柔道与摔跤者皆知：倒地时自身应尽量作曲状与圆状接触地面，而特技人员从高楼跳下，落地时先要顺势翻个跟头。以作缓冲。再举一例，同一玻璃杯，落地毯上不碎而落砖石地面立碎，并非全因硬度不同，而在于前者延缓了作用时间，而使得冲量效果增大。拳击手戴上海绵手套，作用也是冲量原理的运用，否则对拳手造成的伤害未免太大。
因而容易得知：考察徒手格斗对敌人造成伤害可以使用动量的改变，也就是冲量。让我们简单的复习一下动量定理：
假设质量为M的被攻击武士，初始速度为（不管是静止还是运动速度）,在对手的出拳力量F的击打下，做匀加速直线运动。t秒之后，速度为v，根据牛顿第三运动定律F=ma 和加速度公式
A=(v-v0)/t
有
Ft=mv-mv0
因为质量和动量的乘积也就是动量。因此，上边公式也就是：
Ft=p-p0
而力和作用时间的乘积，被称作力的冲量。因此上边公式就是我们在初中时学过的动量定理。它的含义是：物体所受外力与动量的改变相当。
动量定理正适用于研究近身徒手格斗这样的问题。我们可以暂时把拳手的攻击力等同于冲力。因为攻击力作用时间短促，而且随时间变化，因此我们只能衡量它的平均值。
假设武士甲出拳攻击武士乙成功命中，我们来考察甲的杀伤力。
以甲为研究对象。假定甲的出拳初始速度为，力量为B，对乙的冲力，也即杀伤力为H，根据牛顿作用力与反作用力定律，甲受到同样大的反作用力，方向刚好相反。
考察甲的动量变化：出拳速度，命中目标后，在反作用力下速度为v，动量减小为0.
只考虑水平方向上的受力情况，根据上面的动量定理：，Ft=p-p0列式：
(-H+B)t=mv-mv0
也即： (B-H)t=mv-mv0 ⑴
因为v显而易见为0,所以再变换一下，公式变成：
H=B-m（0-）/t
H=B+m/t ⑵
因为m*v0/t 显然为正值，所以H必然大于F。
而且，显而易见，H和拳手质量m与出拳速度成正比，作用时间t成反比。也就是说：杀伤力的大小，要大于出拳攻击力，而且拳手质量越大，出拳速度越快，作用在对手身上的时间越短，杀伤力就越大。
让我们具体举例说明一下：
现在假设已知拳手甲出拳力度F为500牛顿，攻击作用时间为t为0.1秒，甲的质量为100公斤，初始拳速为6米/秒，现在问甲的攻击杀伤力到底有多大？
我们把数值代入算式（2）为：
（500-H)×0.1=100(0-6)
H=500+6000=6500（N）
因此，拳手甲虽然出拳力量是500牛顿，但其实他的杀伤力是6500牛顿。是他出拳力量的13倍。这是相当惊人的。
还应该指出的是，这样计算得出的，只是平均杀伤力。而最大杀伤力要比平均值更大。
这解释了为什么咏春拳为什么强调“寸劲”。而咏春高手李小龙先生的功夫片里，他出拳也完美的阐释了他的攻击哲学：简单，直接，脆快。用最快的速度，最小的作用时间，获取最大的杀伤效果。
双截棍的攻击原理也是如此。这种简单的武器远远比它表面更加具有威胁。
也因如此：衡量徒手格斗杀伤力需要考虑四个因素：
(1)质量
(2)出拳力量
(3)速度
(4)作用时间
第一个因素质量：与重量不同，应该用拳手的密度和体积的乘积衡量 即m=ρν。
而第二个因素：出拳力量，由武士的质量，身体结构，肌肉力量等决定。
第三个因素速度得益于内部驱动，练习。而作用时间，则完全由攻击者有意识掌握。
第四个因素是作用时间。
不需要对函数H=B+mv0/t 进行求导和微分分析，就容易看出：H直接与F正相关。而对m,v0的变化敏感度几乎相同，对这两者的变化牵涉到这二者对t的商。而H对t的变动也相当敏感。这当然还由t本身的取值域（区间）决定。
此外，简单提一下：寸拳的出手应当是由意领身，以身使臂，以全身力量迅速集中于一点，在最短时间及最短距离爆发。而寸劲除刻苦训练之外，别无他法可以获得。“功夫”之语义，与“工夫”同音，这已经指出武术的道路：投入时间和持续的练习。
Chinese martial arts inch fresh lethal physics explanation
Please be patient reader, I promise to use as little as possible in physics terms, formulas. And using basic physics.
I am Chinese martial arts, heavy prime rate and short burst strength. It is based on physics.
Physics, measure kinetic energy, M is the mass, and velocity V power for exponential change places, the sensitivity and importance of particularly great.
Like a bullet, the quality can be said is extremely small, but fast, and therefore destruction is enormous.
But to measure the effect of hitting boxing, whether you just look at the kinetic energy on the line it? That is, as long as the quality of boxers (in general, not less than boxers boxing heavy weight) is large enough, the faster, the greater his lethal it?
Of course not, because it should relate to the concept impulse.
The ancient Chinese martial artists who have mastered this principle from practice, just as we know that before burning chemical formula, already know how to use fire.
So mind, shaped Italy, through the arm, and other various boxing, and even firearms, express' fresh 'forces' are different. Jin, from the force from 巠, 巠 original meaning water clock, cited as a path, clock management, so the strength of the original meaning, that hair cut, there is a path of force. And fresh sound with 'enter', exegesis to the sound of the word with its meaning not every phase away. Jin stressed that it is the power of the 'enter', 'penetration of'. Yaoyan Zhi, fresh sound of the word form and meaning, has expressed its strong mode of use, rules, opportunities and other factors.
Fist to extreme, the same thing, so all our various boxing boxing emphasize the amount of effect. The most obvious to the genus Bajiquan. Octupole collapse made fresh emphasis on essentials, shake, assault. Collapse, such as the potential of landslides; shake, shake shock such as mountain; assault for the usage of a sudden, the action altogether. Force penetration shoulder, elbow, fist, hips, knees, feet in the whole one, the force strength as instant collapse bow hair as a clap of thunder.
Other pass back, Xingyi and other martial arts, there is such a 'cold crisp bomb', 'bombs shake', 'body like archers like an arrow,' 'bar gun such as archery' and other phrases. Even the 'soft run into just' Tai Chi, also 'loose', 'fat power such as throw' language of. For example, issuing knife, after application of the initial force, namely as a momentum to which he served as its self-driving. Then the strength and depth of greater than you with the same force, the handle can cause hand combat effectiveness.
Muhammad Ali once metaphor 'punches to hit like a red-hot iron', is said to be short punches.
In fact, the above said are the impulse maximized.
In addition, Wing Chun Yi Yi "inch King" is known, reportedly because its founder was a woman, the power is limited, so the short bridge narrow horse, boxing output only. The so-called "inch King," that is a short burst of power. Simply put: short distances, short time, explosive power. Only in respect of their physical characteristics, the "King inch" rough when in mechanics "momentum."
Learning Judo and wrestling are known: when the composer fell to the ground itself should be shaped with rounded contact with the ground, while stunt jumping from high buildings, first homeopathic turned a somersault landing. To as a buffer. As another example, the same glass, not broken down on the carpet and fell broken masonry floor stand, not entirely because of different hardness, but delayed the effect that the former time, and makes the impulse effect increases. Wear gloves boxer sponge, the principle of action is the impulse to use, otherwise too much damage done boxers.
Therefore easy to learn: study unarmed combat damage on the enemy can use to change the momentum, which is impulse. Let us briefly review what momentum theorem:
Suppose mass M attack warrior, the initial velocity is (whether it is stationary or moving speed), at the opponent's punching power F blows, do uniformly accelerated linear motion. After t seconds, a speed of v, according to Newton's third law of motion and acceleration equation F = ma
A = (v-v0) / t
Have
Ft = mv-mv0
Because the product of mass and momentum is momentum. Therefore, the upper formula is:
Ft = p-p0
The product of the force and effect of time is called the impulse force. So on top of that momentum theorem formula we learned in junior high school. Its meaning is: to change the object of considerable external force and momentum.
Positive momentum theorem applies to research melee unarmed combat this problem. We can attack boxer temporarily equivalent to momentum. Time is short because the attack force, and change over time, so we can only measure its average.
Suppose samurai warrior armor punching attack acetic successful hits, we examine lethal armor.
With armor for the study. A punching assumed initial speed, strength is B, for B's momentum, that is lethal to H, according to Newton's law of action and reaction, methyl subject to the same large reaction force, the opposite direction.
A study of the change in momentum: hand speed, hit the target after, in reaction velocity v, momentum is reduced to zero.
Consider only the forces in the horizontal direction, according to the above momentum theorem:, Ft = p-p0-row:
(-H + B) t = mv-mv0
That is: (B-H) t = mv-mv0 ⑴
Obviously because v is 0, so then transform it, the formula becomes:
H = B-m (0 -) / t
H = B + m / t ⑵
Since m * v0 / t obviously positive, so H must be greater than F.
Moreover, it is obvious, is proportional to the mass m H and boxers punching speed and action time t is inversely proportional. In other words: the size of the lethal, greater than the punch attack, and the greater quality boxer, punches faster, the role of the shorter time in the opponent's body, the greater lethality.
Let us explain a specific example:
Now suppose that A is known boxers punching strength F 500 Newton, attack time was t of 0.1 seconds, the quality of armor to 100 kg, the initial boxing speed of 6 m / s, now ask A lethal attack in the end how much?
We value substituted into equation (2):
(500-H) × 0.1 = 100 (0-6)
H = 500 + 6000 = 6500 (N)
Therefore, although A boxer punching power is 500 Newton, but in fact he's lethality is 6500 Newton. His punching power is 13 times. This is quite amazing.
It should also be noted that this calculated, but the average lethal. The average value greater than the maximum lethality.
This explains why Wing Chun Why emphasize "inch fresh." And Wing Chun martial arts master Bruce Lee, he punches too perfect interpretation of his philosophy attacks: simple, direct, crisp fast. With the fastest speed, the minimum duration of action, for maximum killing effect.
Attacks nunchaku as well. This simple weapon is far more threatening than its surface.
Because of this: a measure of unarmed combat lethality need to consider four factors:
(1) Quality
(2) punching power
(3) Speed
(4) duration of action
The first factor of quality: with different weight should be measured by the boxers that is the product of density and volume m = ρν.
The second factor: punching power, determined by the quality of the samurai, the body structure, muscle strength and so on.
The third factor speed thanks to an internal drive, exercise. The role of time, is completely conscious grasp by an attacker.
The fourth factor is the role of time.
Do not need to function H = B + mv0 / t were derivative and differential analysis, it is easy to see: H direct positive correlation with F. While m, change the sensitivity v0 almost the same, these two changes involve both the providers of t. The changes to the H t is quite sensitive. This course is taken by the t range itself (section) decision.
In addition, brief mention: inch punch shots should be led by the Italian body to the arm body to body strength quickly focus on one point, in the shortest time and shortest distance outbreak. In addition to hard training and strength-inch outside, no law can be obtained him. "Kung Fu" of semantics, and "time" are homonyms, which has pointed the way of martial arts: to invest time and duration of exercise.