So I have odd question revolved around karate and would love to know if my physics assumptions are correct.
Basically I would like to know what equation to use to calculate the force of a punch when two things happen: when one arm punches out and the other pulls in to the hip while pivoting around the torso, this creates a circular type motion when you punch. The second when you just throw a punch and do more of a linear punch with the second hand staying out. A bonus would be if I can also calculate a radius difference, for example if the second hand pulling back actually comes in closer to the body and increases the force since the radius decreases going from a position of the punch being fully extended to a position where it comes back to the hip.
Someone uploaded this image and I'm no physics major but he talks a lot about linear equations, which seems wrong. I see linear all over it, but also see a note mentioning pivot, so I'm a little confused what its actually showing. I thought this would actually be more of a parabolic (might be the wrong word) or centrifugal equation like so:
So it's clear from this one that if you have more mass spinning like the second hand, the force would also increase. Seems simple but I wanted to see if my assumption are right it if they are actually using the correct equations.
Just as a background I'm a third degree black belt in karate and I'm trying to have a physics based approach to training, so this would greatly help in dispelling some common myths.