# Position of the helicopter

Nstraw
Suppose a helicopter is stationary at certain height And a observer sees it from ground. But after one day the observer again sees the stationary helicopter than will it appear To be at the same Position Or somewhere else

Homework Helper
Gold Member
You need to define what "stationary" means. Nothing is every really stationary...it's all moving around he sun, the sun moves around the galaxy etc..

If you tell the pilot to remain stationary above a point on the Earth he will still be there the next day. If you tell him to remain stationary with respect to the sun he won't still be there (or even on the planet if his helicopter worked in space!).

Nstraw
Just consider the helicopter To be an automatic machine And just standing on the height without any movement. Will the Position be affected by rotation of Earth on Its axis.

Nstraw
Well that helped but the two Are different things And What i interpreted from the article means the Position will change but will it appear To the observer changed as he also rotates with earth

Homework Helper
Gold Member
Just consider the helicopter To be an automatic machine And just standing on the height without any movement. Will the Position be affected by rotation of Earth on Its axis.

If we ignore problems with the way the question is set then yes the helicopter might remain fixed while the Earth rotates below it. Much as the moon remains facing the Earth as the Earth rotates below it.

PS It really does matter how the question is set. In practice a helicopter can't remain at a constant height without the rotor remaining roughly parallel to the Earth surface.

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Homework Helper
Gold Member
Remember that the helicopter and atmosphere of the planet rotate with the planet. A helicopter won't be "left behind" when it takes off. It will continue to rotate with the earth.

The more interesting question is this.. Does the rotor act like a gyroscope and try to keep the plane of rotation constant leading to the helicopter "falling over".

Mentor
Does the atmosphere get "left behind" by a rotating earth?

azizlwl
You can try this.
Inside a moving train, throw a ball vertically and without moving the postion of hand, will it drop at the same position as it left your hand.

Once it tossed up, it left your hand and the train and not connected with anything.