# Calculating striking force

• Iron Dove

#### Iron Dove

calculating "striking force"

Hi i am trying to find the formula for calculating "striking force" (IE punching/kicking). most of the formulas i have come across don't really seem to include all of the factors involved and are typically simply definitions of force (mass)(acceleration). In my mind it seems it may be related to "impact force" and "pressure" rather than just force (although pressure as i have been reading often only pertains to fluids). To me the factors not only include, mass, acceleration, time of contact, but also the density of the contact areas involved. is there anyone more educated in physics that can help me understand this? thank you :)

I think you need to look into "collisions" and momentum and stuff along those lines.

You find pressure in fluids context because for solids the word "stress" is used instead.
For kicking and punching it is hard because the fighters are pushing on the ground during the strike, which is why this is a nontrivial problem to solve.

I'm pretty sure this is best described by force over area or something like that.

So P = ma/A.
And your bones would break depending on a certain pressure threshold.

But then I think that impulse, or force x time, must come in here somehow, because if the object wasn't locked into place, the punch would be weak. But then again, you could apply a force of 1 N for 10 years and not break a board. Too confusing. It has too many factors. For example:

The hardness of the object applying the force is described by ΔF / t. In a force vs time graph, a hard object applies a steep force increase, while a more soft, elastic object applies a less steep parabola-looking spike.

I'm convinced that this problem CAN be accurately defined by force equations, and I don't think you need to use energy, unless you could do something like

Transferred Kinetic Energy / Area

mv2/2A
or such.

I'm very interested in what other people come up with. I've also tried looking up stuff on collisions, but all I could find were momentum stuff.

But then again, we could use mv/A. Worth a thought.

The amount of damage is the amount of energy that is absorbed and dissipated the the receiving body. Of course, the more localized the more intense it is in that area.