Can A Fly Stop A Train?! (more Technical)

[boon racoon]

CAN A FLY STOP A TRAIN?!

[munkee]

Yes.

Close topic.

[yoyoyo]

Haha, my friend gets annoye when i say about this.

[Jay Jay]

how?

[Danny Kearns]

How ?

Dan.

[spangler]

Yep obviously.

And the plane WILL take off

[Dan Clark]

0.9999999999999999~=1

[011001000110010101110010]

if the fly was big enough and man enough to take on a tiny train, yes.

[theone2be]

i'm sooo confused

[Simon]

It all depends on your point of view. First off, from Newtonian physics, there is nothing that says the train must be stationary at any time during the collision. Instead, physics says that the train must only decelerate as a result of the collision, such that the forces on the fly and the train are equal, as per Newton's 3rd Law, "for every action (force), there is an equal and opposite reaction (force)." Since the forces on the fly and the train are balanced, and since force equals mass times acceleration (Newton's 2nd Law), the negative acceleration (deceleration) of the train is tiny because of its tremendous mass. Actually, the splattering demonstrates that this is a completely inelastic collision, and for any collision, the conservation of energy is the overriding rule - K.E.fly + K.E.train = K.E.fly+train + Esplat (heat energy lost to smooshing the fly) - though the resulting deceleration is still miniscule unless the fly's velocity is sufficiently great to give it significant kinetic energy (K.E. = one half mass times velocity squared).

So what about point of view? Well, if the observer is travelling in the train, and the train is travelling at a constant velocity, the observer's frame of reference could be perceived as motionless - after all, the Earth is in constant motion, but our frame of reference is usually defined as fixed. So for the observer on the train, the train is always stopped, until it hits the fly and begins to move backwards. Or, imagine if the observer were travelling alongside the train at a velocity barely less than that of the train. From this reference frame, the train would be moving forward very slowly, until it hit the fly, which caused it to slow to a stop and then reverse. All of this assumes, of course, that the train is coasting along frictionless rails. In reality, the forces of friction require continuous force to be applied to the train to effect constant velocity, such that so small a change in velocity would be quickly compensated by the trains engines' producing slightly more power to maintain velocity. Theoretically, even the smallest deceleration will eventually stop the train.

I'm Pete Wright, and i obviously wrote all that off the top of my head, 'cause i'm god, or, i might of used Google to piss on Boons fire.

[yoyoyo]

Easiest way to explain.

Train's speed: 20mph going west

Fly flying at 5mph eastwards when hits the train. Thus going west after hitting the train.

Imagine it as numbers positive going east negative west.

5 5 0(hits train) -20

There was a big topic about it ages ago, have a search, prob a better explanition.

Edit: Forgot to mention 0 has to be stationary. As both forces are balanced.

Edited November 18, 2006 by yoyoyo

[Jay Jay]

I was just about to say that aswel

[munkee]

It all depends on your point of view. First off, from Newtonian physics, there is nothing that says the train must be stationary at any time during the collision. Instead, physics says that the train must only decelerate as a result of the collision, such that the forces on the fly and the train are equal, as per Newton's 3rd Law, "for every action (force), there is an equal and opposite reaction (force)." Since the forces on the fly and the train are balanced, and since force equals mass times acceleration (Newton's 2nd Law), the negative acceleration (deceleration) of the train is tiny because of its tremendous mass. Actually, the splattering demonstrates that this is a completely inelastic collision, and for any collision, the conservation of energy is the overriding rule - K.E.fly + K.E.train = K.E.fly+train + Esplat (heat energy lost to smooshing the fly) - though the resulting deceleration is still miniscule unless the fly's velocity is sufficiently great to give it significant kinetic energy (K.E. = one half mass times velocity squared).

So what about point of view? Well, if the observer is travelling in the train, and the train is travelling at a constant velocity, the observer's frame of reference could be perceived as motionless - after all, the Earth is in constant motion, but our frame of reference is usually defined as fixed. So for the observer on the train, the train is always stopped, until it hits the fly and begins to move backwards. Or, imagine if the observer were travelling alongside the train at a velocity barely less than that of the train. From this reference frame, the train would be moving forward very slowly, until it hit the fly, which caused it to slow to a stop and then reverse. All of this assumes, of course, that the train is coasting along frictionless rails. In reality, the forces of friction require continuous force to be applied to the train to effect constant velocity, such that so small a change in velocity would be quickly compensated by the trains engines' producing slightly more power to maintain velocity. Theoretically, even the smallest deceleration will eventually stop the train.

I'm Pete Wright, and i obviously wrote all that off the top of my head, 'cause i'm god, or, i might of used Google to piss on Boons fire.

How bout... its an electric train.. a fly gets stuck in the wiring inside the train and causes it to short... so the train stops.

Its a big big big box.. none of this physics shite is ever needed to explain these problems. You could say the fly was sitting on the track.. and the train was previously off balance due to a giant panda jumping on the side of it.. the bump the fly caused as it was run over flipped the train and it stopped when it hit a group of chinese tourists.. who proceeded to take pictures of their own corpses due to the timers on their cameras already being switched on (due to them wanting a photo of them standing by the train as it went past)

The end.

[Mark W]

It may stop a tiny atom or few of glass, but not the train. The glass would slightly rebound on impact, but only a fractionally, tiny amount, but either way: No.

[Barbara Logan-Price]

yes

a man in a fly suit jumps into the tracks and hope the train stops

if the fly got in the drivers eye he would stop the train

[MikeCottTrials]

what if the fly has a tiny atomic bomb strapped to it and its set to explode on impact didnt think about that now did we

[dave85]

How bout... its an electric train.. a fly gets stuck in the wiring inside the train and causes it to short... so the train stops.

Belive it or not, that happens quite a bit

Virgin is a very bad name for a train company, as most of the locos seem to be f**ked...

[Extreme_biker0]

I read that whenever a butterfly flaps it's wings it causes a Tornado on the coast of Indonesia. Surely that will derail a train or two?

[JT!]

Yep obviously.

And the plane WILL take off

NO IT WON'T!

And no a fly cannot stop a train.

And if a tree falls in the woods it will make a sound.

And the egg came first.

[munkee]

Belive it or not, that happens quite a bit

Virgin is a very bad name for a train company, as most of the locos seem to be f**ked...

Yup, has been on discovery channel a few times.

Beleive this or not... leaves are the biggest causes of train crashes ever. (I dont doubt your intelligence.. so im certain you already knew about the leaves)

[Mr_Pitbull]

I watched this video once of a ground breaking experiment about a fly stopping a train, the fly stopped on the front panels of the trains window!

Then the train stopped at the next platform to pick up the passengers then moved onto its next destination! pretty ground breaking stuff.

Edited November 18, 2006 by Mr_Pitbull

[Extreme_biker0]

Yup, has been on discovery channel a few times.

Beleive this or not... leaves are the biggest causes of train crashes ever. (I dont doubt your intelligence.. so im certain you already knew about the leaves)

I saw that.

Yep yep there's a bill currently being pushed through parliment outlawing any deciduous trees within 100m of a railway line. It's expected to come into force sometime in 2008, and will reduce leaf-related rail crashes by 41.8%.

Edited November 18, 2006 by Extreme_biker0

[Radfax]

I have only read the topic title and the first post so i may be comletely wrong but wasnt it some think like if the fly flew at so many hunderd tousands of miler per hour and the train went some thing like 10mph and the body mass of the fly was some thing stupid then it could work?

cant really remeber

[boon racoon]

it was more for the nostalgia of dave finney and the trialskings message board

[Mr_Pitbull]

Im guessing you people think trains just carry on going all the time? you do realize trains stop nowadays dont you, and by the time a fly has stopped a train it would prob be as dense as air.

Edited November 18, 2006 by Mr_Pitbull