Conundrums

[flounderbout]

The last one was silly.
This one is much more interesting. An express train travelling at 120mph hits a mosquito. Since the mosquito is (momentarily) travelling at 0mph, and it is in contact with the train, then the train must also be travelling at 0mph. So do trains stop when they hit mosquitos?
First correct answer wins a prize. And no there are no conveyor belts involved...

[BUSHWHACKER]

Where's Dr Magnus Pyke when you need him?

[slobodan]

De Havilland Mosquito?

[Albannach]

The mosquito cannot (linearly) change direction without being stationary at some point. Therefore, if the mosquito is stationary (whilst it's changing direction) and the train is touching it; relative to the mosquito, the train is indeed stationary.

[shokenore]

What is the prize?

[Albannach]

What is the prize?

Me

[gwh200]

Well I reckon thus.

Make a few assumptions. The train weighs 10000 kilograms and is travelling at 100m/s. The mossie, weighs 1milligram,and is travelling at 0m/s.

The moments of force about these two,

Train-f=ma= 10^6 kgms-2(sorry phone is shite for script).
Mossie f=ma= 10^-9kgms-2

if the potential energy lost is enough to make the train stop momentarily, it's going to be around 10^-60 ish. This is a very small number. There is only something like 10^53 molecules, in the known universe.
Considering chaos theory says there is a 10^80 chance, an elephant will spontaneously appear somewhere...I'm phuqed if I know what I'm on about.

[Albannach]

Well I reckon thus.

Make a few assumptions. The train weighs 10000 kilograms and is travelling at 100m/s. The mossie, weighs 1milligram,and is travelling at 0m/s.

The moments of force about these two,

Train-f=ma= 10^6 kgms-2(sorry phone is shite for script).
Mossie f=ma= 10^-9kgms-2

if the potential energy lost is enough to make the train stop momentarily, it's going to be around 10^-60 ish. This is a very small number. There is only something like 10^53 molecules, in the known universe.
Considering chaos theory says there is a 10^80 chance, an elephant will spontaneously appear somewhere...I'm phuqed if I know what I'm on about.

No change there then

[Apache]

I don't want you, but the train doesn't stop.

The tiny spot the fly hits will deform, stopping briefly whilst accelerating the fly to the speed of the train. It'll be miniscule though as its mass is so much greater than the fly, and speed isn't high enough to do any real damage.

If the train was travelling at a few thousand mph, the fly could well puncture the aluminium (?) panel.

[Albannach]

I don't want you,

Hmph! Not what you said last night...

[Wolfracer]

On top gear tonight, they couldn't get the train moving with the Jag...

...maybe there was a fly involved somewhere...?

[Vultch]

As its the UK rail network... the train hits the mosquito and breaks down bringing the entire network to a standstill...

[Apache]

Only cos its the wrong kind of mosquito...

[gwh200]

Wrong type of conveyor belt...

[gary-r]

this thread is only here to find the explanation for the 3 inch long flat mosquitos on lexurf v1 windscreen after the drive home.

being a member of the lawyery fraternity he never breaks speed limits