Aiight, so I pose this question: does the length of a cannon change the distance the projectile is able to go? Essentially, say we have a cannon eight feet long, and a cannon twelve feet long; the projectiles in both have the same mass and, thus, the same gravitational pull. Why, then, would one go further than the other? I can't be sure my results were entirely accurate, but I found that the projectile with the longer barrel went further than the one with the shorter barrel. Now, though this was inspired by an assignment, it wasn't actually derived from it; more an idea that I need to figure out. I'm trying to relate the impulse/momentum change theory where Impulse=m*deltaV . Impulse=force*time. Now, here's my problem: if the mass is the same for each of the cannon balls, and the same air density resides in both barrels at the time of the blast- how does one differ from the other? Technically, the friction between the interior surface of the long cannon and the cannon balls should decrease the overall change in velocity which eventually translates into impulse and distance and all that jazz. Yet the projectile from that cannon still travels further. The only other reasoning I've developed is that the cannon with the longer barrel also has a greater period of time to accelerate. This is due to the longer period of time that the particles being pushed to accelerate the cannon ball are allowed to hit the cannon ball as it makes its way to the exit for a longer period of time. Thus, the cannon with the shorter barrel, in coherence with this theory, would travel a shorter distance because it's muzzle velocity was less than that of the other; the particles pushing it weren't confined for the same amount of time and dispersed earlier. Now, that would translate into this then: if Impulse equals force*time, and the force behind each of the cannon balls was the same, then the amount of time that the force was acting on it was changed by this 'continuous particle propulsion' idea. Am I totally off, or does the impulse/momentum change theorem apply in another way? Or is it a totally different theory in play? I hope my explanation was somewhat understandable.