Can a fly stop a train?

Question

A fly travels at 5 mph in an Easterly direction and is in collision with a locomotive traveling at 80 mph in a Westerly direction. Presumably, the fly must decelerate (E-W) to zero speed in an Easterly direction and then accelerate (W-E) to say, 80 mph in a Westerly direction. (Give or take!).

If the hapless fly, therefore, continues through a state of being-at-zero mph (stationary) during this process …

DOES THE LOCOMOTIVE ALSO, NECESSARILY EXPERIENCE THIS (stationery) STATE - at this time?

[Note: this is really as philosophical question to which I should genuinely read answers. But, FOR THE SMART-ARSES of this world, who would love to postulate things like 'air cushions' and rotary courses on behalf of the poor fly: PLEASE ASSUME THE EXPERIMENT IS CONDUCTED WITHIN A VACUUM!!]

Don't forget: it is very much a philosophical question. Surely, the fly must decelerate to zero mph albeit only for the tiniest fraction of a picosecond before accelerating ferociously back up to 79.9˙mph. (As Einstein always assumed: "There are no instantaneous interactions in nature").
Therefore, surely - and albeit only for this incomprehensibly tiny packet of time - while the fly is stationery, since both locomotive and fly are now in the same position, so too must the loco' be!

Answer 1

DOES THE LOCOMOTIVE ALSO, NECESSARILY EXPERIENCE THIS (stationery) STATE - at this time?

Of course NOT!

Assuming
1) no momentum loss;
2) the mass of the fly is neglegible;
3) the fly will stick to the train, thus having the same final speed

Writing easterly speed as positive, so the
inital speed of the fly is +5 mph, train is -80 mph.
According to assumption 1, 2, 3, the final speed of both
would be 79.999...

So there is a change in sign (from 5 to -79.999...) for the speed of the fly, which means that the fly will experience "stationary" state. But the train will only experience a loss of speed that is virtually neglegible. So there is no stationary state at all.

Answer 2

No...the locomotive wins this battle...

F=ma----force = mass x acceleration

The train has abundantly more mass and acceleration and therefore hits the fly with an overwhelming force. I assume that by "the fly continues through a state of being at zero mph" that the fly is stuck on the locomotive, but even if it doesn't, the fly had an unnoticeable effect on the locomotive. Therefore the locomotive continues on at 80mph

Answer 3

To answer your question: No, the locomotive will not pass through 0 in velocity. It will however, slow down. This slow down will be immeasurably small. But, it is still present. The fly will, pass from its forward velocity through 0 and then on into negative relative velocity. This all happens instantaneously over just a small minuscule amount of time.

Answer 4

This is a relativity question.
The fly would never reach a a state of zero direction relative to the ground, nor would the train.

Answer 5

The fly would never stop in relation to the ground, it would just reverse direction. And the train's forward motion would be affected only in an immeasurably small way.

Answer 6

Good question and I would say no. But give the fly a lever large enough and he could move the world.

Answer 7

i don't think the fly would ever be in a stationary state. it would be travelling east, then quickly travelling west. very quickly.

the train would experience no effect or drag at all.

have a nice day.

Answer 8

Fly wins, it is Superfly!
The only thing that we know absolutely is how little we actually understand.
¥☺¥

Answer 9

How big is the fly?