# Hyperbolic curve

1. Aug 18, 2009

### snazzy1981

A train is travelling at the speed of a bullet.

A man, stood on top of the train, fire's a gun in the direction from which the train has come from. (facing rearward)

He pulls the trigger the instant the train passes station 'A'.

The velocity of the bullet relative to the ground is 0

To an observer standing on the platform (mind you, in a perfect vacuum) the bullet would drop.

In our imperfect world, the bullet would drop about 2/3 of the way and then follow the train in a hyperbolic curve.

would someone mind plotting curve ?. I am a simple web developer and this has got me curious as it was a question posted on my own forum... thanks

Last edited: Aug 18, 2009
2. Aug 19, 2009

### fatra2

Hi there,

Why would your bullet, in our imperfect world, would travel 2/3 of the way. The bullet is fired backward at the speed of the train => the bullet's speed compared to someone in the station would be 0. I don't see any reason for it to suddenly be bothered by friction, since it has no velocity compared to the still air surrounding. Of course, I base my assumption on the fact that the bullet leaves the barrel at the speed of the train, friction in the barrel not considered.

Can you explain the reason for this. Cheers