Bullets typically weigh between 20 and 40 grams. In addition, we can calculate kinetic energy as KE = m * v^2, which means the velocity changes exponentially relative to the mass (I think I incorrectly assumed a linear relationship before).
So in your thought experiment, the 19kg to, say, 19g transformation would change the velocity by a factor of 1000^0.5, or about 32. 32 * 4.4m/s = 140.8 m/s, which is totally reasonable (slower if the bullet is heavier, not sure about the density of a cannonball).
Bullets typically weigh between 20 and 40 grams. In addition, we can calculate kinetic energy as
KE = m * v^2, which means the velocity changes exponentially relative to the mass (I think I incorrectly assumed a linear relationship before).So in your thought experiment, the 19kg to, say, 19g transformation would change the velocity by a factor of 1000^0.5, or about 32. 32 * 4.4m/s = 140.8 m/s, which is totally reasonable (slower if the bullet is heavier, not sure about the density of a cannonball).