Ok so I think I have heard this "Statment" now about 20 times and I think it is complete , This is it:
" If you take a gun and shoot it straight up in the air
It will come back to the ground, but moving twice
as fast, as the speed it came out of the gun"
I know this is complete But I just need someone to verify, just to make sure there isn't a whole explination to why it falls twice as fast as it went up.
My "Hypothesis" if you will is that when you shoot a gun up in the air, the bullet was forced by the expanding force of blackpowder, But once it reached the falling point, there was not another force push it back down other then gravity. Which means that the maximum fall speed is around 150 mph tops, which is 204.39 FPS nearly nothing a gun can even achieve since it is such a low speed.
You are correct, I am not sure about your numbers, but the fact is that an average bullet is fired at many many times the terminal velocity (maximum achievable speed from falling). It has no means to accelerate to any speed beyond its terminal velocity if it is accelerating only as a result of gravity. Mytbusters did a segment on just such an experiment. Not to say that Mythbusters are the supreme court of the physics world, but they did do this one. And because people who will argue this fact arent the sharpest tools in the shed, the best way to convince them they are wrong might just be with the talking box.
Mythbusters Episode 50, "Bullets Fired Up, Vodka Myths III"
Unofficial Mythbusters: Episode 50: Bullets Fired Up, Vodka Myths III
Given enough space, even a bullet fired straight down, will decelerate to its terminal velocity.
Saw that Mythbusters ep, the gist was all their straight up and down tests "proved" getting hit with a falling bullet was not fatal. However they had a surgeon who presented several cases where people had been hit in the skull with a "falling bullet" and died or been severely injured. I believe those were actually the result of bullets fired at an extreme angle to the horizon, not straight up. Just like Elmer Kieth using a .44 magnum revolver to shoot deer at 1000 yds plus, the trajectory resembles that of a mortar but there is still initial velocity from the shot behind the bullet.
Well said Kernel.
Originally Posted by kernelkrink