Originally Posted by eawoodall
I have answered this question many times.
basic physics
moment arm = weight times length from focal point ==measured in pound feet.
torque = rotational energy measured in foot pounds.
to hold a 100 pound weight still at the end of a 1 foot long pole requires 100 foot pounds of torque because the 100 pound weight at the end opposite the end at which the force is exerted has 100 pound feet of moment arm.
energy = mass times distance.
rate of change of distance is v.
e=(mv^2)/(2) kinetic energy.
the velocity squares the energy of impact. The mass only multiplies.
you hit with twice mass you two times harder.
you hit with twice velocity you hit four times harder.
you hit with twice mass and velocity you hit eight times harder.
you hit with three times the speed and hit nine times harder.
velocity is much more important than just mass. And that is before considering if you move that fast you can hit them before they can hit you, even if they start to swing first!
and the smaller the surface area the more pounds per square inch for the same amount of applied force so a smaller amount of contact area with target hits better than a wide contact area, if you want to increase pounds per square inch.
p=mv. Momentum equals mass times velocity
also consider the movement of the hips, shoulders, legs, length of stepping forward, or the arc distance of angular velocity when pivoting, in your calcutations of distance moved.
if you are off the ground (like in kendo), and let whatever you make contact with become the point of you trying to stay off the ground (put your body weight into it) then you have put your entire body weight into the blow (strike). And your entire body weight is more force (f=ma==w=mg.weight is mass times gravity, and a type of force, i.e. has the same dimensionality or units) than most people bring to a strike.
I hope this helps. Eawoodall
