Posted in Keep Cape Safe on November 11, 2012
Even though arrows travel about one tenth as fast as bullets, they are able to inflict deeply penetrating wounds. Why? Physics may help us to answer this question.
With any projectile weapon, damage to tissues depends on the projectile’s momentum. We remember that momentum equals mass times velocity. More weight, more momentum; more speed, more momentum.
On the other hand, once a projectile enters the body, its ability to penetrate tissue is inversely proportional to its “force of drag.” High force of drag, less penetration; low force of drag, deeper penetration.
In fact, force of drag increases exponentially with increased velocity. Compared with a bullet, an arrow’s momentum (its ability to cause harm) derives more from mass, less from velocity. Since arrows travel about ten times more slowly, drag is 100 times less than for a bullet.
Of course, many variables determine accident severity. An understanding how arrows are capable of inflicting deeply penetrating wounds is one more reason to vote against bow hunting in Cape Girardeau.