# Flies on the school bus

Ever since I was a kid on the school bus I have wondered how flies can travel on buses and other moving vehicles without being squashed against the rear window. Even on a school bus traveling 55 MPH it seems they can get around without a problem. I am no physics scholar but it seems to me that the second the fly became airborne on a moving bus the fly would have to travel the speed of the bus to stay in the same place relative to the bus. Or travel faster than the speed of the bus to move toward the front of the bus ( assuming the bus is moving forward ). Do flies move that fast? How do they know how fast to fly? Do flies comprehend the dangers of the rear of the school bus moving toward them?

They have no problem flying around inside the bus for the same reason you don’t get a 55 MPH wind in your face when the bus is speeding down the highway. The air inside the bus IS moving right along with the bus at the same speed. You don’t notice it because you are, too.

Duh, that makes alot of sense. I was making it way too complicated.
Thanks, now I can sleep soundly

Those flies are flying in the air contained by the bus. That air moves with the bus, so the flies are scarcely affected by the bus’s speed.

There are some effects when the bus accelerates, brakes, or turns. But (just as for passengers on the bus) the effect is small and easy for a fly to handle.

Probably because of their very light mass they have very little momentum/inertia.

This is the second thread I’ve seen you post a nitpicky inflammatory response to me
than for no other seeming reason than to be a horse’s ass. If this is typical of this
board (and in some ways it is I’ve found) then I won’t be back after my g.m. expires.
It ain’t worth it. :wally

My point is simple: if you consider a songbird, and it’s flying around inside the bus,
if the driver then slams on the brakes the bird will likely slam into the front window.
If it is a hawk it will likely shatter the windshield. The fly has much less mass hence
much less momentum and won’t suffer the same fate (at least to the same degree).
Now the OP didn’t quite take it that far, but the stationary “wind” thing is only part of
the story.

You read more into the OP than what was there, hence the retort. All that was asked was why a fly wouldn’t have difficulties flying around inside a bus that is travelling at 55 mph. The answer (that the air is carried along with the bus) applies whether you’re talking about a fly, swallow, or vulture (assuming the vulture would fit ).