If a bird flew into a railway carriage would it have to hover or fly at the speed of the train?

Question

And why is this?
Thanks for your help.

Answer 1

It is a newtons first law problem. U know that particle always continue going in the same speed in the straight line unless some external force change its velocity.
if a particle is going with the speed of the train then it will continue to move with same speed.

when a train is moving then the air inside it strikes the walls of moving train compartments and start to move with it.Even if the window in the train is kept open then also at every instant the air coming in for replacing the air going out hits the walls and continue going with the speed of the train.

now when a bird flew into a moving train then it also strike either directly at walls or at with the 'air of train'. since the train moves with a speed greater then the speed of the bird so it puts the force on bird and changes its speed up to its own speed.

once the bird attain speed equal to the speed of the train then it always moves with the train itself.

if the train is accelerating then until the bird attain speed of train the train itself attain some greater speed. so train continuously keep on applying force on the bird.

Answer 2

The air in the carriage is travelling at the same rate as the train so the bird can or would fly at a speed relative to the air it flew in so if it flew in the same direction as the train was travelling it's speed over the ground would be the speed of the train plus it's speed through the air. However the earth is spinning at the same time so if the train was travelling from west to east then the speed of the earth at that point would also be added. At the same time the earth is travelling round the sun so that speed must be taken into account. The sun is travelling round the centre of our universe carrying the earth with it so that speed needs to be considered. And of course our universe is travelling away from the site if the big bang at an incredible speed and taking the sun, the earth, the train and the bird with it so it is not quite clear without considerable calculation exactly what speed or in what direction that bird is actually travelling

Answer 3

That depends upon the *air speed* inside the carriage.
Typically, carriages have zero (or near-zero) airspeed relative to the train. Thus, as soon as the bird enters the carriage airspace with its new velocity, the requirements for lift would be with respect to the air in the carriage. However, if the carriage was wide *open*, the wind whipping through would be close to the speed of the train, and that bird would have to fly at that speed to hold its position.

This question is like asking: if you run very fast and jump onot a moving train, do you need to keep running at that speed once you are on the train in order to stay on the train. The answer is "of course not."

Of course, relative to the ground (not the train), the hovering bird and the successful train jumper *are* moving as fast as the train!

Answer 4

Easiest way to think about this is to imagine a time when you've been in a car going down a motorway, and you've noticed a fly or a gnat or something inside the car (which was already in it before you set off). It's flying about all over the place, with little or no effort, and similarly, provided you don't have the car window open ;) you don't feel the rushing of wind over your face - due to air having a much lower density than the car's metal and glass shell, the air inside the car is moving at the same speed as the car itself. So, the air is trapped inside the car, and moves along at the same speed.


When I was a kid, I used to think about this for HOURS whenever I was on a long car journey... It drove me mad!


Here's a little Brucie Bonus for you: if you're ever on a train, try and get to a carriage which has a long pathway with windows where you can see out. Get on the train, and then as it's pulling out of a station, or moving off from some points, walk in the OPPOSITE direction to the direction the train is travelling in, and look out of the window at a static point. If you can walk at the same speed as the train (but in the opposite direction), that sensation is REALLY WEIRD! But really good fun... Like walking down an up escalator, travelling without moving. =D

Answer 5

The bird would have to hover. The flight of the bird is relative to the air around it; since the air inside the railway carriage is moving at the same rate as the carriage, the bird would not have to fly forward to maintain its position in the railway carriage.

Answer 6

Consider first the case of a bird already in the car even before the car started moving. And say the car moves at 60 mph.

If you have a bird in a cage in a moving car and you open the cage, it will fly around normally because it already has obtained the 60 mph velocity of the train since the bird in its cage started moving when the car started moving.

Now, on the other hand, if we have an open window and a different bird flies in through the open window of the car, then likely the bird will be hit by something in the car, or hit by the back wall of the car, because the bird has not acquired the 60 mph velocity of the moving train.

That bird will have to work awfully hard to avoid being hit by the back wall of the moving car, just the same as if it were a baseball approaching him at 60 mph.

Best for that bird to quickly fly out of another open window!

Answer 7

If the bird flies into a carriage and hovers in mid air without touching carriage its forward velocity will be 0 mph. i.e. it is not moving forward or backwards.
However the carriage is moving forward and therefore the rear of the carriage will strike the bird.
The bird would have to fly forward at the same speed as the carriage to avoid being struck by the interior of the carriage.

Answer 8

If the train continued to travel at a constant speed without changing direction, the bird would only have to hover.

However, if the train were to make a turn, slow down, or speed up the bird could no longer merely hover and would have to correct itself by moving to the side or slowing itself or accelerating respectively.

Think about a a set of dice hanging from the rear-view mirror in a car. When the car speeds up and slows down or turns, the dice move. When driving on the freeway at a constant speed, the dice hang vertically.

Answer 9

If we entered a railway carriage should we run at the speed of the train?

The bird to enter into a moving train has to adopt the same method as we do to enter a moving train.

Answer 10

No, not after they get in the carriage.Try an easy experiment. Rub some dog crap on the inside of your car & leave the window down just a little. wait an hour or so.When the car is full of flies,get in & quickly roll up the window. Now get out on an open piece of road & bring her up to about 70MPH. Now stomp on the brakes. amazingly no flies will be dashed on the window. Dont forget to wear your seatbelt The air in the carriage is going as fast as the carriage, so when a bird flies into it ,the bird is automaticaly going the same speed