RECOIL

RECOIL, or REBOUND, the starting backwards of a firearm after an explosion. Mersenne tells us, that a cannon twelve feet in length, weighing 6400 lbs. gives a ball of 24 lbs. an uniform velocity of 640 feet per second. Putting, therefore, $W\; =\; 6400$, $w\; =\; 14$, $V\; =\; 640$, and $v$ = the velocity with which the cannon recoils; because the momentums of the cannon and ball are equal, we shall have $Wv\; =\; wV$.

$V$; and so $v\; =\; \backslash frac\{wV\}\{W\}\; =\; \backslash frac\{24\; \backslash times\; 64\}\{6400\}\; =\; 2\backslash frac\{1\}\{2\}$; that is, it would recoil at the rate of $2\backslash frac\{1\}\{2\}$ feet per second, if free to move.