If a Helicopter......... ? ?

Question

Stays in the air.. and just stays there all DAY. forget about gas and all that. and since we know the earth is moving... will the Helicopter move from position and end up in the other side of the world? or would he just stay there bkux of gravity?

I know it might be a stupid question.. but i have ask a lot of people and they don't seem 2 know..

sorry for any errors....

Answer 1

Think this through. The Earth, at middle latitudes is rotating at about 700 mph. The helicopter is supported by the air. Either the air is moving along with the Earth and will carry the helicopter with it, or the Earth is moving at 700mph relative to the air and there's a 700mph wind blowing just off the ground. Which do you think it is?

Answer 2

When the helicopter is on the ground, it moves with the Earth.  There are no significant forces from the rotation of the Earth because everything is going in the same direction.  When the Helicopter takes off - straight up, it still has that hundreds of miles per hour momentum it had when it was on the ground.  And, the wind is also more or less going with it.  So the helicopter goes around the Earth over one spot without any particular effort.

There's a great NOVA program where Feynman talks called "The Pleasure of Finding Things Out".  He talks about momentum a bit.  He explains that objects with mass in motion tend to stay in motion, and if at rest tend to stay at rest.  This is the phenomenon.  But no one has any idea why it works that way.  It's not a stupid question.  It's one of the basic properties of the way the Universe works.  We're spending billions of dollars on projects like the LHC to figure this kind of stuff out.  How stupid is that?

Answer 3

If there is wind, the helicopter will be blown whichever way the wind blows, just like a balloon.  If there is no wind, the helicopter will move relative to the ground below it because of the coriolis effect.  How much it moves and the direction will depend on the latitude it took off from, how high it flies, and how long it hovers.  I get accused of being too complicated all the time here, so I'll give the simplest example (trust me, you don't want the complicated one).  

If the helicopter takes off over the equator, the helicopter will move slowly westward along the equator.  You probably are wondering why it would do that.  Well, Coriolis is the answer.  You are probably saying to yourself, ask a stupid question, get a stupid answer.  But if you've read this far, you're game to hear more.

The deal is that when the helicopter takes off, it has the eastward velocity of the Earth's surface.  As it ascends, it maintains that eastward velocity.  However, it is now decoupled from the surface of the Earth, and as it goes higher, the distance it needs to travel to maintain its position relative to where it took off from becomes larger since the radius of the circle around the center of the Earth it is traveling is larger.  Since its velocity to the East is what it was when it took off, it loses ground relative to the surface and appears to move to the West.  It is, in fact, still moving East, just not as fast as it needs to to keep up with the surface below it.  

If you think that is a pointlessly complicated and stupid explanation, you should hear what happens if the helicopter takes off from something other than 0-degrees latitude (i.e., north or south of the equator).  Then, it not only moves west, but north or south (depending on hemisphere).  You've suffered enough, I'll stop now.  

Coriolis will spin your head around.  heh heh.  Nobody ever thinks coriolis jokes are very funny.  Pity really.