I am intrigued by the physics of boxing, and why some people with fast hands do not have good punching power, ie, can not knock other boxers out.
I feel there are three major components of a punch The equations involved, I think, are: $$F= ma$$ $$KE= \frac 12 mv^2$$
Velocity of the fist: As velocity goes up, the force or energy of the punch goes up exponentially. So, fast hands are optimal.
Elasticity of the punch: You want the impact to be fully elastic, that is, all the energy gets transferred to the other boxer's chin. Energy gets lost by bad technique - the fist and/or wrist and/or elbow and/or shoulder deflect, crumple, get compacted, get knocked off on a vector. (I think this is why most boxers do not have maximal power - they make have poor impact technique).
Mass: This is where I have difficulty. At first I thought this was easy, because the only part of the body that is moving on a vector straight at the chin is the boxer's arm. So, mass, I thought , would simply be the mass of the boxers arm. BUT, boxers are trained to move their whole bodies forward as they punch. If so, and if at the moment of impact they lock all their muscles and make their whole moving body rigid, does this mean that effectively their entire body mass influences the kinetic energy of the punch? IOW, is the apparent mass of the arm increased? Or is just the arm the proper measure? If you get clipped by the side mirror of a moving car, you do not experience the mass of the entire car, right?