• Archive through September 30, 2001 September 30 - 03:12 pm [20]

rIGht.

In hapkido we use an break for an test of soft
power where you place an board in your tub half
filled with water and you slap it with your palm as lightly as you can and still break it.
It's harder than you may assume.The water
provides a very firm support surface for the
board to rest upon. And no you do not bake the
board or let it soak to soften it either.
Give it an try.

Take a piece of toast, put it in the middle of a bowl of red jello, try to break the toast without disturbing the jello before your kid tries to eat it.

Bob,
Have you ever considered writing a book on martial arts? You should. I find your training methods and insights both unique and...very practical.

take care,
Brian

Power equals mass times distance over time.

If I threw a .5 oz dart at you and also threw a
.5 oz wet pasta noodle- which would have the most power?

Physics definitions:

Force = rate of change of momentum (dp/dt for those with calculus).
This is the same as F = ma where you assume the mass is constant

Impulse = Ft (F=force, t=time)
so the same impulse is the result of a large force and a short time, or a small force and a long time. There is no recognised term "impact"

Torque = r x f (the cross denotes a vector product and that it is the part of the force perpendicular to the radius - the straight line joining the point where the force is applied and the fulcrum around which the force acts - that counts, nothing else)

Pressure = force/area (so same force over smaller area = larger pressure)

Power = rate at which work is done or energy is transferred (dE/dt for those with calculus)

Energy is more likely to be kinetic rather than the potential mentioned above
KE = 1/2 m v^2 (1/2 times mass times velocity squared)
PE = mgh (mass times gravity times height)

So, thinking in terms of power, we either get more power by moving faster, or by transmitting in less time. Just another way of looking at it if you're so inclined

I would like to add that if you attempt to use a powerful strike on someone who is wearing a chest protector for example, it is not only important how they feel, but also how you feel. For example if your shoulder, wrist, etc. hurts you were not properly aligned & therefore not issuing the maximum amount of power that you may be otherwise capable of.

RobT= Impulse has always been an interesting phenomenon to me. I heard a story once where a fellow put a board on his chest and had a buddy drive over him at high speed. He walked away with relatively minor injuries, because the impulse was low (don't try this at home).
I would imagine that the principle of impulse could be could be applied to a strike. Perhaps a "pulled" punch versus a punch where force is continued even after contact is made.

Many physical structures in the body are good under dynamic tension, but propergate cracks under static tension.

Bones are an example of this.

As long as the dynamic compression/ tension does not exceed a certain critical limit of course

RT

The original title of this thread was "How doe we measure Power?". Simply stated - by its effect. Looking at Power using the Force equation is purely a quantitative value and leaves out the dynamic nature of the MA's

I weigh in at approximately 270 lbs @ 6'-2" in height. If I had the proficiency to do a whole body one knuckle punch we could possibly experience 270lbs/sq in (someone else can do the math) for example. Of what value is this if I'm not touching someone? Consider Power as the intelligent use of Force, ie, four catties...

Is it not consistent to view Power in the MA's to be Force magnified by timing, position, distance, alignment, and target selection? Don't these qualities define the dynamic interaction between combatants? Doesn' the concept of Force in a way imply a "double weighted" mindset?

It takes 7.5 lbs to break a knee, or there abouts. A light slap to the testicles can double you up. For those of you who have young children, these two examples bring back memories, eh? To me, Power is all of these and more.

As we are human beings, some forms of effectiveness come from social and psychological rather than physical causes. Should we include these in the measurement of power?

I seem to recall Chen Man-Ching saying (in reference to the four ounces concept) that you can lead a thousand-pound bull with a four ounce ring in its nose. But there is no way you could move a thousand-pound statue of a bull with a four ounce ring.

Then there is all the talk of 'empty force' and you see the videos of teachers manipulating their students - whatever the causes, there is an effect! And what about the accounts of enraged, psychotic and/or drugged individuals absorbing multiple 'fatal' bullet wounds and continuing to wreak havoc until actual point of expiration (see the book Ayoob Files for example). In the same book there is a case of a man who died from a relatively minor gunshot wound in the arm, convinced that he had been fatally shot.

"It is dangerous to look at a fight as a purely physical phenomenon" - Tony Blauer

Anybody else ever experiment with the hitting the newspaper stunt? Take a full sheet of newspaper, hold it up high by one corner, let go and hit it with the hand which was holding it.

If the strike isn't fast enough, the paper will be pushed away. On a good day the paper can be torn in half along the seam. Usually just a hole, although sometimes with my hand goes through it.

This is also a good test to see if you are getting too tight, as from too much weight training to the detriment of your other training.

I have heard of something similar where a sheet of 8 by 11 paper is suspented and punched.

I like to try it several times a week to make sure that I stay 'loose'.

you're loose alright.