Or would the back glass slam into it when the car moved forward?
What? Like on a treadmill?
When a fly is trapped in your car, it doesn’t slam into your back window. God knows I wish it would. Seems to me that it’s the same as your hypothetical helicopter.
I’m just glad that I’m not the only one concerned with the ramifications of miniaturazation on helicopters.
What frame of reference? Relative to a stationary car, relative to a moving car, or relative to the ground? There has to be a frame of reference for there to be an answer. But if it’s hovering in a stationary car so that’s it is also stationary with respect to the ground, yes, the car then accelerating will have the back window hit the helicopter.
Any device (or creature) that is supported on air moves in relation to the air. Do you feel the air move past your face as you drive with the windows up? The helicopter would hover stationary to the relative speed of the air (which, inside the car has a relative speed of zero).
Before this thing goes all to hell, we need a definition of “tiny” and the materials that it is made of.
I was told that a helium balloon will actually move forward in a car that accelerates suddenly because the air gets compressed to the rear and it “rises” to the front.
Conversely, a 5 pound helicopter with an incredibly powerful motor will tend to have much more inertia that makes it stay in place and hit the rear.
It is an interesting question. The helicopter is flying in its medium (air) and that medium is moving so, under most circumstances, the helicopter will move with it. We just don’t know the rate of change given the variables.
I am a perpetual flight student and I always read about it in the academic sense. One thing that most people have trouble imaging is that sustained wind does not blow against the plane. The plane is in the air and will move with it just as a boat in a current does. However, we have several factors to work with here and the change is sudden.
No way, dude. A hovering helicopter exerts force only relative to the vertical axis. If the car and the air in it moved up or down, then yes, the helicopter would stay stationary. But if the car moves in any lateral motion, the helicopter moves relative to the car. Perhaps the motion is attenuated by the “wind” produced, but it will move.
Clarification… would oscillate around, and eventually return to, its starting point. It wouldn’t be exactly stationary.
By analogy to lighter than air balloon which moves forward when car accelerates, heavier than air helicopter should move back.
What if the windows were down? Wouldn’t this decompress the air inside the car and prevent the helicopter from staying in place?
You need to draw a distinction between a car that is accelerating, and one that is moving at a constant speed. In the constant speed case, the helicopter will hover just fine. If you are accelerating, all kinds of wacky things happen. First, feel yourself being pressed back into your seat when you accelerate? The helicopter will feel the same force. So yes, it will be slammed into the back of the car when you accelerate, unless you compenate with the helicopter.
I don’t believe a helicopter of any mass could match the balloon trick. The balloon does what it does because it’s floating in air - it’s bouyant. A helicopter isn’t. A balloon will respond to differential changes in air pressure, and a helicopter won’t (at least, only a tiny fraction as much).
At a constant velocity with the wind kept out, a helicopter hovering in the car has absolutely no idea how fast it’s going. In fact, neither does the car, since it’s also rotating with the earth, orbiting with the earth, orbiting the galaxy with the solar system, and moving through the universe with the galaxy.
This sounds like a job for the Mythbusters.
What about a tiny helicopter inside a plane on a giant treadmill.
I was thinking about a plane…if you were on a plane and standing in the aisle and jump up, the back of the plane won’t slam into you. But what if the plane was not pressurized?
if you jumped up and the plane took off while you were airborn you would deffinitly hit the back wall, or at least fall on your ass.
f=ma.
What is the force?
What is either the mass or acceleration?
Different windows open or closed are going to create different pressure drops. If the helo was tilted away from a pressure drop and it was utilizing similar force it would not move.
More data is needed to answer this correctly.
If the little helicopter pilot wants to live, he will work hard to keep the back window from hitting him or the front window, depending on if the car is accelerating or decelerating. When it’s motion is constant, the helio will be in a hover unless it is really itty bitty and can fly around like a fly. But if it is the size of a fly, what about it’s mass and ability to overcome the 3 G’s of acceleration produced by the 454 ground pounder? Maybe it could handle all a 350 could deliver? Is it a Bell, Hiller, Sikorsky, Hughes, or some other design? Is it NOTAR? turbine or piston? How big is the car?
We need more info …
Just in case anyone doubts the answer that upon acceleration there would be movement relative to the car, consider whether you would leave a hot cup of coffee without a lid on the dashboard as you either braked hard or accelerated quickly. It’s an even more stable situation than the helicopter (friction and air molecules trying to keep the cup in place instead of air molecules only for the helicopter), and the cup would certainly move/tip.
I always thought an insect’s flight as it flies into a moving car through the window showed amazing agility.
Seems like an interesting question that one can test easily with a RC helicopter and a semi trailer.
I think we can all visualize a helicopter hovering inside a semi-trailer, and if the trailer had the back doors opens while it moved forward, the helicopter would most certainly remain stationary as the truck drove off.
-Tcat