RECOIL, or REBOUND, the starting backward of a fire-arm after an explosion. Merfennus tells us, that a cannon 12 feet in length, weighing 6400 lb. gives a ball of 24 lb. 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; we shall have (because the momentums of the cannon and ball are equal) Wv = wV; and so v = \frac{wV}{W} =

\frac{24 \times 64}{6400} = 24; that is, it would recoil at the rate of 24 feet per second, if free to move.