Impulse

I never stopped to realize that karate has something to do with physics. Every time I throw out a punch, I am exerting an impulse that is equal to the amount of force I put in to the punch multiplied by the amount of time I exert that force for. Impulse is equal to the change in momentum. Punching someone is almost like a sticky collision and momentum is conserved no matter what, so the initial momentum should equal the final momentum. Also with this in mind, almost all of my punches exert the same impulse, but the stronger punches are the ones with more force done in less time, rather than the ones done with less force in more time, so quick jabs are much more effective in sparring. I always knew that fast punches seemed much stronger than the ones I took my time on, but I never knew the reasoning behind this until we recently started learning about momentum and impulse.