October 29, 2004
I have had countless arguments with really smart people who just can't accept that bullets don't make you fly across the room if they hit you. Oh sure, they'll KILL you. But you won't go stunt-plowing through a wall.
Conceptually, think of it this way: The momentum the bullet imparts to the guy who gets hit has to be the same as the amount of momentum the gun imparted to the guy who fired it. Did the guy shooting the gun go flying the other way? No!
The math is right there in the comic, but here's a bit more detail:
I used the stats of a Desert Eagle, because it's one of the more powerful handguns available. Different ammunition varies the muzzle velocity, but a good average seems to be about 1640 ft/s. That works out to be very close to 500 m/s. As for the weight of the slug, again, different ammunition has vastly different weight. But most of the weights seemed to hover around 240 Grains. Yeah. I didn't know what the hell a "Grain" was either. Turns out it's about 64 milligrams. Do the math on that, and you'll get about 15g.
Armed with those numbers, and presuming a 220-pound (100kg) victim, that gives you a velocity of 0.075 m/s, which is about 0.16 miles per hour.