Imagine a fly, flying along a train track heading exactly east.
Imagine a train, on the same track heading exactly west.
Train hits fly, fly squishes onto train.
Fly goes from moving in one direction, to completely the opposite.
Fly must have been stationary at one point when direction changed. (Like throwing a ball up in the air)
Fly was in contact with train at the time.
Errrr, what? The train would have slowed down a fraction (and i mean a fraction), but wouldn't of stopped.
If you model it as a particle, then as the Fly is stationary so must the train be for a split second - meaning the fly stopped the train.
In real life, however, the fly would have been stationary, but the train would of carried on going and simply compacted and crushed the fly into a giant splat.
The fly doesnt stop moving, it is deflected. Specifically different bits of it are deflected at different times - which with a slow motion camera is quite a sight.
I'm so bored I just worked it out - assuming the fly weighs 10mg, and flies at 4 KPH, and the train weighs 100 tons and travels at 50 MPH then the change in speed of the train is so miniscule it won't even register on my calculator.
EDIT - The train slows down by 0.000024656-ish MPH. AKA over 120,000 times slower than walking speed. In terms of a 50 MPH train, negligible.
Sure. Just calculate 1.0 - 0.99999999... Start writing down the decimals, and in a day or so you will see the answer.
Yes, each part of the fly was stationary at some instant during impact. But when its tail was stationary, its head was already going in the opposite direction. And perhaps the first few layers of atoms on the train were also stationary for a very short moment.
In all of those cases, you will be dividing by zero somewhere along the way.
Yes I know that 0.9999999.... "tends" towards 1 but the fact of the matter is that it is NOT actually 1 or you would just write 1 instead of .9999......
Does not matter how many 9s you write does it will NEVER reach 1 therefore it is not 1.
It is more to the fact that it is not possible to fully represent 1/3 in base 10 hence the rounding error in the maths that allow 1 / 3 = 0.333333... when infact 1 / 3 != 0.3333333...