The Physics of Slapping
Please enjoy this video demonstration.
The breakdown:
Here we see the wind up. There is a lot of Potential Energy stored up in Mackenzie's muscles and that gets transferred into Kinetic Energy as she swings her arm toward Maya's face.
The hand approaches the face, converting even more PE into KE, but never loses any energy (some gets turned into heat energy), and Maya flinches in anticipation.
Like the surface of a pond has tension, so does the face. If you toss a rock into a pond, it creates a rippling effect. And so does a slap to the face! The face has properties of inertia that allows the skull to move independently of the face in a situation like this so the skin follows later as you can see in this much more professional picture:
Once the hand has reached the maximum velocity or velocity desired, it stops exerting energy and relies on the momentum of the hand.
After the impact, the head is turned in the direction of the slap. Luckily, this object in motion does not stay in motion, or we would have a decapitation and a second (and fourth) degree murder case on our hands. Her neck stops her head from spinning off and she returns back to her normal self, though maybe slightly emotionally damaged.
