As I lay in bed last night, my foot was struck by a projectile moving, near as I can figure, somewhere around 20 feet per second*.
Well, that's not much... but this was, roughly speaking, a 120,000 grain projectile, so it had the momentum of, say, a 230 grain projectile moving at around 10,000 FPS**.
Owwwww.
Not as injurious as a 20 million grain projectile at 20 FPS (small car, 14 MPH, yeah, that'll hurt), but still.
At least it was blunt. And the kinetic energy was that of a 230 grain projectile at (pokes calculator again) 450 FPS. So, frontal area does seem to have been a large factor in the lack of serious injury.
Maybe I should stop lying so close to the edge of the bed. A bit further inboard, and the ballistic fuzzballs would miss more often.
* Half a second to traverse a 10-foot hallway? 20% the top speed of a cheetah? Sounds plausible***.
** According to Hollywood physics, the impact must have blasted me out of bed, up into the air, and out through the bedroom window, scattering bits of glass and window frame everywhere.
*** Noted later: XKCD gives the top speed of a housecat as 13 m/s, or about 42 FPS. So Huckleberry could plausibly have been going a fair bit faster than I'd guesstimated. He's a big fast critter.
Comments