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A fly travelling in a car

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badly1004 | 09:58 Thu 14th Jun 2007 | Science
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A fly is flying around inside a car and that car is travelling at 60mph. The car crashes into a wall, does the fly hit the back window or does it continue flying around unaffected by the car's abrupt stop?
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How could the fly hit the BACK window?

It would move forward and hit the windscreen.
Imagine you were in the car. You would hit the windscreen if the car crashed into a wall.
The fly and the air in the car are travelling forwards at 60mph. When the car is stopped by the wall, everything in the car is still travelling at 60mph, until something stops it, like the windscreen.
it hits the front window dummy!
Recalling my exam years its all to do with momentum. This is derived from mass x velocity. Because the mass of the fly is very small the momentum value will also be very small.
Loosehead � � � or whoever you are � � �

Better think twice before labeling someone a dummy.

The fly perceiving the eminent danger of the approaching wall would instinctively turn about and fly in the opposite direction never being dissuaded in any case by the clear glass in a window.
Actually, the fly has no concept of how fast the car is moving and isn't directly affected by the momentum or inertia, other than the fact that body of air inside the car in which he's suspended does have a small amount of mass and therefore would continue forward when the car comes to a sudden stop. However the small mass of the air would not be enough to force the flying insect into the suddenly stopped front. window (or the back of Mr. or Mrs. Bagley's head...) in my opinion...
kwicky, does this mean if Loosehead was riding in the aforementioned car, that his body could be destroyed from the impact, but his brain (like the fly) could make it through unscathed? Now who is the crash test dummy?
Sorry, but you are all wrong, the fly who has very large eyes would see the wall coming and nip out of the side window and into the car going in the other direction. He would later make a statement to the police, saying that the driver was at fault. He would then claim for whiplash injury from the drivers insurance.

I know it happened to me! Honest
The relative velocity between the fly and the wall is 60mph and that's the speed at which it will hit the wall when the crash occurs.
Given the very good job done by crumple zones in modern cars, and considering the drag coefficient and relatively small momentum of the fly, the low compressinbility or air, I think that the fly would decelerate almost as quickly as the car etc and would avoid the front window...

However, Similar to one of the previous answers... I think that in the fly's panic and will to escape the burning wreck, it would hit all of the windows in the car.
Of course, we all omitted to ask some crucial questions... was the car travelling forwards? Which direction was the wall coming from? Schoolboy errors....
All I know is it's not the best way to swat the fly.

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A fly travelling in a car

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