The bullet will travel to wherever the muzzle was pointed at the moment of disharge.
If a gun is fired into the air at a perfect right angle to the earth, the bullet will travel straight up until it stops and falls back to earth. When the bullet reaches the ground, it will be travelling at the same speed as when it exited the gun. Being hit with this bullet would be the same as being shot.
Yes it does ! Even if both bullets are identical and fired from the same make of gun, the one in the plane will already have the velocity the plane is travelling at before it's fired.
If fired from a rifled firearm, it spins.
Are you assuming that it keeps travelling at that speed?
Damage. How much depends on the gun that fired the bullet that hits it. it probably would explode
A bullet fired from a gun
When a bullet is fired upwards vertically it gains kinetic energy.
Probably. The bullet would be travelling slower than when it left the gun (see related question) but it would still be travelling fast enough to cause injury. In areas of the world where guns are fired into the air in celebration injury from falling bullets is not uncommon.
The bullet fired from a gun has greater horizontal acceleration. For vertical acceleration, they are both the same.
A bullet will usually stay together when fired, at least until it hits something hard enough to shatter it. If you're asking about what happens to a round of ammunition when fired, it's a bit different. At the very least the bullet will separate from the shell casing. There may also be some filler, and maybe some unburnt powder that gets ejected.
I used gelatin or a large water tank.
When a bullet is fired into the sky, it will eventually stop becasue it has run out of energy and fall back to the ground.