Hovering in a moving vehicle.

So the other day my friend and I were at Carl's Junior (god I love their food) when he posed a question that he'd read: If a hummingbird were to be hovering inside of a moving car would it simply hover there as it would if it were outside, or would it slingshot to the back of the car. Now, my first thought was that no, it could not possibly just hover when it's hovering in a space that is constantly moving. Seemed reasonable enough. Then I started to think about it more. Have you ever dropped something in your car? Thrown something in the air? It doesn't slingshot to the back window of the car. It usually goes up and comes down

Now I am by no means a mathematician and have pretty much forgotten every thing that I learned in physics, so I was wondering if anyone could seriously answer this for me (in detail preferably). Please and thank you?

Newtons' First Law of Motion.

I. Every object in a state of uniform motion tends to remain in that state of motion unless an external force is applied to it.

It goes to the back. It slingshots back since it's basically staying at the same altitude by its own energy. Stuff you drop/throw change altitudes, so they don't slingshot.

It would depend on how much friction the air would produce on its wings. Technically, it'd just tend to remain in its place, but then again, consider that the air in the bus moves along with it. I'd love to see the results, though, but most likely, the poor bird will meet the back.

As the hummingbird would be in the lee of the vehicle it would remain hovering.

The interior of the vehicle serves as a vacuum of sorts for all intents and purposes, the external forces are redirected by the shell.

Now if you were in a jeep or a convertible with said hummingbird and released your top, the bird would be slung out the back.

Err... it would depend on which frame of reference it began hovering.

If the hummingbird was touching a surface on the car while it started moving and then got up and hovered, it would retain its forward momentum and appear to hover in place relative to the car. On the other hand, if it was outside and entered the car through a window or something, it wouldn't have any forward momentum, so it would slam into the back of the car (or more accurately, the back of the car would slam into it).

Also similar to what Eosian said, the air inside the car would be moving at the same speed as the car, so (assuming my first scenario) the bird wouldn't feel any air resistance, allowing it to retain its forward momentum without any extra effort. In a convertible the air would be still relative to the Earth, i.e. moving backward relative to the car, so air resistance would push the bird toward the back.

As the hummingbird would be in the lee of the vehicle it would remain hovering.

The interior of the vehicle serves as a vacuum of sorts for all intents and purposes, the external forces are redirected by the shell.

Now if you were in a jeep or a convertible with said hummingbird and released your top, the bird would be slung out the back.

I guess we can agree that the acceleration is what determines the result, too.

I guess we can agree that the acceleration is what determines the result, too.

A simple helium balloon demonstrates the case fairly well enough. Anyone who's ridden with one will have thought nothing of the fact the balloon wasn't sucked to the back of the vehicle (unless a window was opened to create a pull or there were some fairly extreme driving going on that jostled around the internal air pressure).

Okay. That makes a lot more sense. Thanks, guys