If a helicopter rmains stationary at the same place for say 2 hrs,any change in relative position wrt earth?

Question

point is as helicopter remains stationary for two hours, the earth under it rotates ( its natural axis rotation), the points /articles under it will change its position wrt helicopter or not? Say helicopter is lifted from the top of a hotel then even after two or more hours of its lift , it will still be above the same hotel? If yes, what about the rotation of earth on its axis?

Answer 1

The earth is approximately 25,000 miles around at the equator. It rotates once a day, or once every 24 hours. That means that a point on the equator makes a 25,000 mile circle in a 24 hour period. It's moving over 1000 miles per hour.

Do you notice a 1000 mile per hour wind outside your window?

No. The air mass against the surface of the earth is moving along with the ground as the earth turns. Wind is not the result of the ground moving along underneath. However, there are absolutely effects on wind patterns that result from the earth's rotation. I'll say a litte more about that at the bottom.

When the helicopter leaves the ground, it is invested with the same initial velocity as the earth beneath it and the air above. There is no relative acceleration to the east or west if it just goes up a ways into the air.

What's more, a helicopter's ability to hover is dynamic. The wind is constantly trying to push it a little bit one way or another and the pilot is constantly correcting it. Your pilot would visually align the helicopter on top of the hotel and then keep it there. The reason that it doesn't float away is that the pilot is constantly moving it back over the hotel, despite the breeze that wants to push it away.

The rotation of the earth DOES affect the air though. Even if you wouldn't be able to see it happen with your hovering helicopter, you can see it on the weather maps. This is called th "Coriolis Effect". It's very interesting.

A circle around the earth's axis of rotation AT THE EQUATOR is about 25,000 miles in circumfrence. Up at a point in Canada somewhere, you could find a point which makes a circle around the axis of rotation that is HALF that in circumfrence. At the north axial pole, the circle of rotation is ZERO circumfrence.

Suppose you lived on the equator and you wanted to fire a missile to land on the north pole. You aim your missile due north and launch it. As it leaves the launcher, it's going north at a 1000 miles an hour, but it's also rotating with the earth beneath it at a rate of over 1000 miles an hour eastward. By the time it's passing over Canada, it's still going north 1000 miles an hour, and east 1000 miles an hour... but Canada is only going 500 miles an hour around the earth since its up on top of the spherical rotating globe! The missile has a relative eastward turn!!!

As things fly north, they veer east becasue they're moving eastward faster than the ground underneath. This is why storms rotate clockwise in the northern hemisphere (and why they rotate counterclockwise in the southern hemisphere). As winds (huge air masses) push north from the equator, they veer east and start rotating clockwise. This is called the Coriolis Effect.

Nice question.

I hope that helped.

Answer 2

Yes, I agree with what tunips says...

You must define the term: stationary...

Generally, a helicopter pilot will alter the thrust of his rotors to remain stationary over a particular object...

The helicopter is moving all the time, in fact!

The pilot constantly adjusts the direction of his aircraft to maintain his altitude & location relative to that object...

Because the earth and the air are moving at approximately the same speed (with respect to the rotation of the earth), the helicopter does not need to compensate for it.

Answer 3

Well, wouldnt the helicopter still be within the gravitational pull of the earth, meaning wouldnt it rotate with the earth. If that is true, then it wouldnt move relative to the earth at all.

Answer 4

The Gravitational pull of the Earth will "Lock" the Helicopter to the Earth, therefore moving the helicopter with it.

Answer 5

If the helicopter is stationary with respect to the ground, then it isn't going anywhere by definition. If it is stationary with respect to the air, then it will drift about on the winds. If it is stationary with respect to the sun, then it will rush away from the planet at 30,000 Km/h.

Answer 6

It will indeed be above the hotel, since the rotation of the Earth is very slow.

Answer 7

You should read newton's law of gravity. :))