Momentum does =mass * speed, but energy is mass times the velocity squared. (K= 1/2 * m * v * v). By maximizing the velocity at which you strike your target (bag or opponent), you will be applying the most energy possible. This is why it is important to be at the correct distance from your target - if you're too close, you won't have enough space to maximize your hand speed, and if you're too far, your hand will be slowing down. While going up in weight, you can increase the mass, but the speed has a greater influence on the energy you will hit with.
i think you get to types of punchers guys like foreman ,gerrald mccllenan and julian jackson who seem to punch through the target with power or fast fights like tommy hearns who threw his punches with amazing speed and power .
so speed equals power for some but not all fighters .
increased speed will mean increased power but power alone dosnt necessarely come with being fast and vice versa
