Hi everybody, I'm trying to calculate the spontaneous energy of a projectile fired by a rifle, handgun, or a canon. The amount of the powder in the cartridge is known and with a reasonable assumption of the following we can calculate the initial pressure produced in the chamber as the rifle fired: "For every 10g of powder, there will be 3.2 litters of gas produced in the chamber" The next step is to find the Force acting behind the bullet with known caliber. Next, we can calculate the initial acceleration using F=m*a. So, now that we have the acceleration, how do we calculate the velocity of the bullet right at the start of firing. I have forgotten the formula. Could somebody please answer this question. I'm grateful if you would be kind enough to write the formula. Thanks. P.S. All dimensions are known: Calibre, mass of bullet, length of the barrel, etc.