Announcement

Collapse
No announcement yet.

Do you really believe in gong fu?

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • #31
    Indeed, F=mass x acceleration.

    But to assume that the force is constant is a mistake. If F was constant, as mass increased, accel would decrese. What you guys are saying is that the force is the same because m is less and a is greater...this isn't necessarily the case. In this comparison, it would make more sense to say that a is constant. Therefore, if a stays the same, those with the greater mass m, would generate more force.
    Becoming what I've dreamed about.

    Comment


    • #32
      Originally posted by Chicken
      its not just muscle mass or density, albeit that that is a big issue defensively. Impact does damage, that's weight x speed. Seems to be the case in all nature, that there is a law of diminishing returns "the bigger the slower".
      Technically, it's not weight, it's mass times acceleration. But given our constant gravitational pull, it's a moot point, unless one was fighting while falling off of a building (weight being a factor of acceleration, or gravity, and mass). As most peoples hands are relatively equal to some degree size wise, the change in velocity of the punch, when it hit you, would be a more deciding factor as to the amount of force that was generated. The position of the hand during the strke itself would dictate how much "penetration" one would have; a palm, with a greater surface area, would not impress as much as a ridge hand strike.

      But this physics equation is not as relevant as the kinetic energy one, when it comes to hand or other strikes. The amount of energy that a punch would have would probably be more along the lines of one half mass times velocity squared. When the punch hits the opponent, and is eventually stopped, the kinetic energy turns into potential energy, which is what causes tissue disruption. The amount of energy imparted in a strike is therefore more dependent upon the speed of the punch, than the mass of the hand/arm/body combination, though, you can see from this equation, that a large individual, who "puts his weight" behind his strike, can impart more energy than a smaller individual who throws his strike with the same speed.

      The faster the strike, the greater the energy imparted. Mass plays a role, but because velocity is multiplied by itself, a change in that would give rise to a much more significant change in energy applied in the strike.
      Experienced Community organizer. Yeah, let's choose him to run the free world. It will be historic. What could possibly go wrong...

      "You're just a jaded cynical mother****er...." Jeffpeg

      (more comments in my User Profile)
      russbo.com


      Comment


      • #33
        Actually initial kinetic energy+work=final kinetic energy. Work I belive is zero in this case. So the initial kinetic energy equals the final kinetic energy. I don't believe there is any potential energy conversion. Potential energy is more of a gravitational thing, where GPE=mgh (mass x gravity x height). Momentum equations also come to play here,

        P=MV

        Where P is momentum, M is mass, and V is velocity. The momentum someone has when they hit you is more or less transfered to you. Changing the surface area being struck concentrates or generalizes this momentum/energy transfer.

        Would you rather be backed up into by someone at 10 m/s, or poked by that same person travelling at 10 m/s?

        Energy and momentum are closely related and are often used in the same breath.

        I'm more inclined to say that momentum plays a greater role.

        If you set a basketball down and throw a tennis ball at it, the tennis ball bounces off, while the bball rolls away. They both felt the same force, due to a Newtonian Law, but one felt the greater change in accel. Now make those balls people. Who do you think felt it more?

        Maybe I'm getting my examples mixed up. Feel free to correct me, nerds. :P
        Last edited by LeiYunFat; 03-28-2007, 01:53 AM.
        Becoming what I've dreamed about.

        Comment


        • #34
          LOL

          Why don't you start studying powerlifting instead of learning some Kung fu or anything of this kind?

          Because according to what you say, the only way of beating a muscle guy is to be as muscled (big fast and strong) as him. Well this equation is then solved, the bigger i am the better chance i have to defend myself against anyone.

          But is that really so simple? Why are there so many martial art clubs when the solution is actually to lift 150kg barbells all day?

          The guys might be strong and fast and all the shit, but if i'm a the top of my form and well conditioned i stand a chance, i don't say i'll definitly win, i say i have a chance -or why the **** did i waste my time training everyday? And what about all the others who train like me?

          Most of the time, people see strenght as you guys do, the more the better. But man, if you're precise, you don't need to be that strong to knock someone out...Exepted if you really wanna not only knock him out but behead him at the same time!

          I, being a light middleweight, so not particularly big, nor small, can affirm being able to knock down a guy that is twice bigger than me in one or two strikes. If not in one or two strikes, they would be enough to hurt him enough so he couldn't fight anymore or he would open so i can finish him.

          Even with half power, using an elbow for example...I mean, a strike is a strike, a chin is a chin, a throat is a throat, and a dick is a...Whatever your size is, i guarantee you'll feel it!

          I have seen many guys in the gyms you know really really bulky, impressive. These ones couldn't fight at all i am sure of that, they barely can move their hudge arms around. Their range of motion is really tiny i i totally agree with Chicken on many things that he said.

          However, Leiyunfat's example is ambiguous because his muscle guy is an olympic weight lifer and must have a tremendous speed as he doesn't only train for showing off his boobs (well that's not sure though). But there are not many like him, honestly, there are many more of these bodybuilders around.

          example in this video that proves a good strike is definitive strike, and that it is the goal we should all set to ourselves as Martial Artists, this kind of skill:

          http://www.youtube.com/watch?v=4D5GmHaDGH0
          The East? The West?

          Men and Women, that's all...

          Comment


          • #35
            Yes, but that kinetic energy has to go somewhere when the fist stops (when it hits the opponent). That energy just doesn't disappear; it is transmitted into the fist / opponent combination, and it provides disruptive force to the tissues in both.

            OK, physics was a long time ago, but when a mass that has kinetic energy stops, I thought that energy then became potential energy. Correct me if I'm wrong.
            Experienced Community organizer. Yeah, let's choose him to run the free world. It will be historic. What could possibly go wrong...

            "You're just a jaded cynical mother****er...." Jeffpeg

            (more comments in my User Profile)
            russbo.com


            Comment


            • #36
              It does, IF we're talking about objects moving up or down. The only potential energy I am aware of (I'm not an expert, but I have studied it) is gravitational potential energy, mgh. If you have a bouncy ball and drop it, it's kinetic energy goes up and it's gpe decreases as it nears the bottom. On it's way up, it's gpe will increase as the KE decreases, until it reaches apogee, where all energy will me converted to GPE and there will be no kinetic energy.

              The same is not true for people throwing blows at eachother.

              Flow, take it easy. We're talking about CONDITIONING. What you were ranting about was skill over conditioning.

              And to answer your first question...I don't just study powerlifting (the examples I posted were examples of olympic lifting...a totally different animal), I apply my knowledge. But that doesn't make me any less of a martial artist than you seem to want to believe. I simply took the things I thought were important and started training them. There are many, many, MANY ways to can train with weights, and each will lead to a different emphasized result. Lifting to get big is not always the same as lifting to get strong.

              And what's with that, anyway? What's with the aversion to weight lifting so prevelant in the ma world? Is it the lack of mystery? The conformity to a different kind of image?

              Lifting and training in a similar manner has done nothing for me but highten my ability to show my skill. That's what I think martial artists should be striving for.
              Becoming what I've dreamed about.

              Comment


              • #37
                F=MA talks about the force applied to a mass to make it accelerate at the rate shown in the equation, and is irrelevant in this issue.

                Ke=1/2mv^2 in this instance relates to the amount of energy the mass of your arm has if it moves at a given speed. body mechanics/skill/proper delivery of the blow allows more or less of this kinetic energy can be delivered to the target which will then be converted into several forms of energy; kinetic(moving them backwards and causing movement within the body), sound (thwack!!), thermal(energy is transferred to molecules making them vibrate faster causing increase in temperature) and potential(energy going into the bonds between molecules causing them to stretch vibrate and with enough energy break, on a large enough scale causing tissue/organ damage)

                i think, am a little out of practise.

                Comment


                • #38
                  I've never heard of that kind of potential energy, but the consensus is that it exists. The stretching and vibrating is not potential energy as it as kinetic and maybe some spring potential energy (1/2kx^2). At least that's what I've been taught. Moving objects don't really have potential energy.

                  Actually, like I said earlier, momentum might be more suited for this discussion. Momentum P is the change in force over the change in time. But...momentum and energy are often discussed in similar ways, so we might be wasting our time.

                  To go back to what I said in my previous posts, I think pressure=Force/Area. The less area, the greater the pressure. The greater the area, the less pressure. This explains punches as opposed to body slams or something, as well as puncture wounds and shit.
                  Becoming what I've dreamed about.

                  Comment

                  Working...
                  X