PDA

View Full Version : Riding in Cars With Bees

SolomonGrundy
10-19-2001, 01:42 AM
Warning: this is a stupid question, probably answered hundreds of times before elsewhere, but I don't know where to start looking.

So a bee gets into my car at a stop light. It's hovering around, annoying me. The light turns green and I step on the gas. Why doesn't the bee get thrown back into the back seat? I guess what I'm basically asking is how is the bee flying -- is it exerting forces on the air around it (which I would assume would get "left behind" as my car moves forward), or is it somehow exerting a force on the surfaces in the car?

Every check on Google for "bee flight" gives pages that either describe it from a behavioral or evolutionary standpoint, or assume a basic understanding of aerodynamics that I obviously don't have.

douglips
10-19-2001, 01:48 AM
Originally posted by SolomonGrundy
I guess what I'm basically asking is how is the bee flying -- is it exerting forces on the air around it (which I would assume would get "left behind" as my car moves forward), or is it somehow exerting a force on the surfaces in the car?

Do you feel a rush of air on your face when you step on the gas? If not, what makes you think the air in your car gets left behind when you step on the gas?

All the air in the car accelerates with the car, so the air is not left behind. The bee will certainly feel some acceleration, but it is not being washed backwards by a wave of air. My guess is that you would need to undergo much greater acceleration in order to see a difference in the bee's flight path.

For more fun, try driving around with a helium balloon suspended in your car. It will go forward when you step on the gas.

TheNerd
10-19-2001, 01:52 AM
From the frame of reference where the car is stationary, the bee (and you and the air in the car) experience a backward acceleration when you hit the gas. But, practically speaking, the bee doesn't have a whole lot of mass or inertia, and the effects of the air in the car will be quite important.

Since the air in the car stays pretty much motionless with respect to the car (I don't feel a breeze inside the car when accelerating, do you?) the bee can remain fairly unpreturbed by the acceleration.

Achernar
10-19-2001, 03:13 AM
I'm not distrusting anything anyone said, but now I'm confused. The helium balloon doesn't have a lot of mass or inertia either, but it does move with respect to the car. So would, I imagine, a CO2-filled balloon hanging from your car ceiling. What's the difference between that and a bee?

hibernicus
10-19-2001, 04:02 AM
The difference between the CO2-filled balloon and the He-filled balloon is that the helium balloon has much less mass than the air it displaces, while the CO2 balloon has more mass, and therefore more inertia.

As you accelerate, there is a tendency for the air (and anything else) in the car to move towards the rear of the car. The air pressure in the rear will be greater than that in the front. This forces the He balloon forward, while the CO2 balloon moves backwards.

The bee has not much inertia at all, but does tend to move backward also as you accelerate. Of course, as you stop accelerating and move along at a steady speed, the bee experiences no net forward or backward force and can fly equally well in any direction.

So to answer your question, there is no difference in principle between the CO2-filled balloon and the bee.