This may sound dumb to some folks, but lets say I fire a gun. 1000N of force goes into the bullet, and another 1000N of force goes into my body. Even if i strap the gun to the ground, it will just apply 1000N of force to move the earth by a tiny amount. Because of this, does it mean that it isn’t possible to have 2000N of force going to the bullet with the same parameters as before?
In: Physics
Let’s break this down. A chemical explosion occurs, releasing heat, gases, and particulates. This mixture wants to occupy more volume than it has available, so pressure rises, exerting a force on all sides. The weakest point of the round fails and we now have a two body system. The bullet is pushed down the barrel. That same pushing force was on all sides of the casing, which is snugly held by the gun. The force moving the bullet is the same force acting on the gun. How things respond to pressure forces is based on mass, inertia. The bullet has very little mass compared to the sliding mechinism of a firearm. So that force acts to accelerate the slide back a little, while accelerating the bullet forwards a bunch. More energy transfer occurs to the lighter object relitive to the bigger object because of inertia. For a perfectly ideal situation, the ratio of energy transfer is the same as the ratio of masses. What Newton’s 3rd implies about this kind of system is that some energy is going to be “wasted” moving the bigger mass, but the bigger that mass is the less you have to dump into it. You can’t get anywhere without leaving something behind.
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