Dionysusigma
Member
A.K.A. Dumb questions in kinetic energy transfer
As I was relaxing this afternoon, I was playing Deus Ex and good 'ol Doom 2
, and a thought came to me (at first, I thought it was just a headache, but with pictures).
So anyway, there are two main types of energy, potential and kinetic, and both can exist in different forms. Potential energy can be anything from a mass held at a height, chemically stored, and so forth. Kinetic is light, motion, heat (particles in motion), etc.
Reading different threads on this board, I found that pistol calibers coming out of barrels that were longer than their original intended use (i. e., a 9mm from a 20" barrel) may actually be hindered by that added length by slowing them down. Likewise, larger calibers coming out of a much shorter barrel (7.62x54R out of an M44) can leave a lot of the powder unburned.
Kinetic energy can transfer from object to object, sometimes changing its form: Car tires (kinetic energy is their rotation) spinning on a concrete surface (friction) causes heat (another form of kinetic energy).
Also, the Heisenberg Uncertainty principle may apply as well--using a photon (light) to determine a particle's (friction, in a sense) location and/or state will invariably change that particle's state... example: You like to play pool in the dark, and have a glow-in-the-dark cue ball. The racked balls (which are not glow-in-the-dark) are the mass you are measuring with the cue ball. After the break, you know where the cue ball made contact with the racked set, but you have no idea where the numbered balls are now. The cue ball's energy (motion) is directly responsible for their change of state (motion, change of location, etc.)
Tie this into a gun: energy is put into the bolt/slide/whatever when you, the operator, charges the gun (kinetic energy). That energy is transferred into the striker/hammer, and stored as potential energy. That energy is released (kinetic motion) when you pull the trigger, causing the hammer to fall on the firing pin (kinetic motion) and detonate the primer and eventually the powder (chemically stored potential energy now being released as heat).
The gases inside the cartridge expand due to the heat, forcing the bullet out (kinetic heat/motion of expanding gases transferred to projectile). As the bullet moves down the barrel, the barrel gets hot (due to friction between the bullet and rifling, and heat from the gases). The bullet leaves the gun, followed by the expanding gases that propelled it, which results in (more often than not) muzzle flash.
That's what gets me. If a 9mm is hampered by a long barrel to the point it slows down, shouldn't there be no muzzle flash? If the projectile is being slowed, that tells me that the burning powder/expanding gases aren't doing their job, so to speak. They aren't pushing the bullet, so they must be losing their energy. Why, then, does the flash still happen? For that matter, why is it still comparably loud?
Someone please inform my ignorant self... why, oh why? :banghead:
As I was relaxing this afternoon, I was playing Deus Ex and good 'ol Doom 2
, and a thought came to me (at first, I thought it was just a headache, but with pictures).So anyway, there are two main types of energy, potential and kinetic, and both can exist in different forms. Potential energy can be anything from a mass held at a height, chemically stored, and so forth. Kinetic is light, motion, heat (particles in motion), etc.
Reading different threads on this board, I found that pistol calibers coming out of barrels that were longer than their original intended use (i. e., a 9mm from a 20" barrel) may actually be hindered by that added length by slowing them down. Likewise, larger calibers coming out of a much shorter barrel (7.62x54R out of an M44) can leave a lot of the powder unburned.
Kinetic energy can transfer from object to object, sometimes changing its form: Car tires (kinetic energy is their rotation) spinning on a concrete surface (friction) causes heat (another form of kinetic energy).
Also, the Heisenberg Uncertainty principle may apply as well--using a photon (light) to determine a particle's (friction, in a sense) location and/or state will invariably change that particle's state... example: You like to play pool in the dark, and have a glow-in-the-dark cue ball. The racked balls (which are not glow-in-the-dark) are the mass you are measuring with the cue ball. After the break, you know where the cue ball made contact with the racked set, but you have no idea where the numbered balls are now. The cue ball's energy (motion) is directly responsible for their change of state (motion, change of location, etc.)
Tie this into a gun: energy is put into the bolt/slide/whatever when you, the operator, charges the gun (kinetic energy). That energy is transferred into the striker/hammer, and stored as potential energy. That energy is released (kinetic motion) when you pull the trigger, causing the hammer to fall on the firing pin (kinetic motion) and detonate the primer and eventually the powder (chemically stored potential energy now being released as heat).
The gases inside the cartridge expand due to the heat, forcing the bullet out (kinetic heat/motion of expanding gases transferred to projectile). As the bullet moves down the barrel, the barrel gets hot (due to friction between the bullet and rifling, and heat from the gases). The bullet leaves the gun, followed by the expanding gases that propelled it, which results in (more often than not) muzzle flash.
That's what gets me. If a 9mm is hampered by a long barrel to the point it slows down, shouldn't there be no muzzle flash? If the projectile is being slowed, that tells me that the burning powder/expanding gases aren't doing their job, so to speak. They aren't pushing the bullet, so they must be losing their energy. Why, then, does the flash still happen? For that matter, why is it still comparably loud?
Someone please inform my ignorant self... why, oh why? :banghead:
