Shooting a bullet from a train?

Question

If I am on a train travelling at 1000kph and I shoot a gun having a bullet speed of 1000kph out the window in a direction directly opposite to that which the train is travelling, would the bullet simply fall to the ground theoretically speaking? Please refrain from discussing issues of wind ripping my arm off etc.

Quite the plethora of answers. To clarify for some of you who didn't read the question correctly, the bullet would be fired towards the back of the train and on the outside. I'm asking if the bullet would drop relative to the ground outside. So no 2000kph scenarios.

Answer 1

yes. To an observer standing on the ground beside the train the bullet would appear to fall straight down. (assuming you fire the bullet exactly opposite the train and ignoring wind effects.)

velocity is a vector. vectors are additive. 1000 kph in one direction + 1000 kph in opposite direction = 0 kph. the bullet would accelerate to the ground via gravity.

to an observer on the train, however, the bullet would appear to travel at 1000 kph.

Answer 2

Yes! Before the cartridge explodes, the bullet is travelling at 1000kph along the track. After the explosion (which imparts a velocity of 1000kph in the opposite direction) the bullet receives this velocity which must be added to the velocity it already has. So we get the sum
final velocity = 1000kph-1000kph = 0!
To you on the train, the bullet is moving away from you at 1000kph. To someone on the track, the bullet mererly falls to ground. You could think of a different experiment- how about shooting a rocket from the earth in a way similar to your bullet? The possibilities are endless!

Answer 3

im not 100% sure but it sound as if, theoretically it should fall to the ground as the speed of the bullet exactly matches the speed of the train. sorry i couldnt be anymore help than that. also, you might have to take into account that the bullet would loose speed the longer it is out of the gun, so maybe it would go in the same direction as the train but at only a few mph.

Answer 4

That's a tricky one... it makes sense that as the relative speed to someone standing next to the track is zero, but to the person firing the gun, the bullet will look just as it would if the gun was fired from a standing start.

Laws of relativity etc.

Here's a thought, If a train hits a fly that is flying towards it, does the train stop for an infinitely small amount of time seeing that the fly has to decelerate to 0mph before reaccelerating in the other direction?

Answer 5

To you the bullet will have a 1000 kph speed and you will see a nice parabola.

To someone standing on the ground the bullet has velocity of 0 kph and just falls to the ground.

Answer 6

you could shoot a person at the back of the train. the gun would go off the bullet would stop and the person would run into the bullet,, this would be to an observer on the ground outside the train. the person who fired the gun it would be the same if the train was not moving at all.

Answer 7

No.

Actually the bullet will still travel. At the moment you fire the gun, the barrel of the gun is stationary relative to the bullet leaving the gun. It MUST be this way in order to propel the bullet forward. Because of how quickly the barrel is moving relative to the GROUND, however, there will be much more distance between the bullet and the gun by the time the bullet comes to rest, than there would be if you were standing still on the ground to fire the gun.

Remember that at the moment you fire the gun, even if you're moving at 1000kph, you're still at a fixed point when you fire the gun, and the bullet is going to travel away from that fixed point.

Here's another illustration. That same train is travelling but instead of holding your hand out the window, you shoot a "bad guy" that is trying to rob you at the other end of the car. You're still able to shoot him. If your theory of the bullet simply falling to the ground were true, you wouldn't be able to shoot the guy in the back of the car.

Answer 8

this is really a question about frames of reference, when you fired the bullet, from your frame of reference it would appear to be moving away from you at 1000kmh, however from the frame of reference of a spectator on the ground beside the train, the bullet would indeed have a horizontal velocity of 0 and would simply fall to the ground due to gravity.

Answer 9

There's about 10 people here that say it falls to the ground, and 8 say the bullet does not drop to the ground. I did a simliar count to another Asker's question about whether or not we've landed men on the moon, and amazingly, about the same percentages believe that we did, and did not. Then again, it's no coincidence at all.

Answer 10

Gravity still applies and so does air resistance.
It's a vector addition problem on top of a f=m times accel problem.
The bullet would remain in the air for it's normal flight duration. Relative to your location it would be speeding away at 1000kph
Since you have defined a bullet which does not accelerate from the gun, it would emerge from the barrel, and fall due to gravity, when seen from a still reference point.