punch physics
elastic collision: Vf = (2m/(m+M)) · v
target accel
(7ms impact)
-- g
your punch
4.00 m/s
headshot
baseline
--
(5 kg, 8 m/s)
Based on Natale (2026), arXiv:2607.18276. Elastic collision model. Concussion threshold ~70g brain acceleration over ~7ms impact duration. Effective mass is the portion of body mass dynamically coupled into the strike — a teachable technique, not a fixed number. Doubling effective mass (5→10 kg) gives 1.71× target velocity; increasing speed 25% (8→10 m/s) only gives 1.25×.