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Physics question (1 Viewer)

What do you think

  • Both aircraft will arrive at the same time

    Votes: 11 33.3%
  • One aircraft will arrive before the other.

    Votes: 22 66.7%

  • Total voters
    33
Wind is a result of the Earth's rotation, so if you don't take that into effect then the rotation is negligible as both planes are already starting at the rotating speed. Any acceleration and continued acceleration would be equal at that point.

 
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Wind is a result of the Earth's rotation, so if you don't take that into effect then the rotation is negligible as both planes are already starting at the rotating speed. Any acceleration and continued acceleration would be equal at that point.
Wind is the result of differences in atmospheric pressure from the effects of uneven heating.  I will grant you that rotation, via the Coriolis effect, will influence directional aspects of wind, but I would not attribute the existence of wind to rotation.

 
Two identical aircraft leave the same exact time from an airport on the equator and circumnavigate the earth. One goes east the other west. Now for simplicity we will take all winds and weather and fuel out of the scenario. Both aircraft will travel the same exact speed, same exact altitude same exact track (with the exception of where they pass at 180 degrees around the globe (they just miss each other at that point) .

Will one aircraft arrive back at the starting airport before the other, taking in the rotation of the earth as a possible factor?
There are exceptions.

Okay to close ticket.

 
I voted different times based on earths rotation - unless I’m misreading (somewhat possible) or I’m an idiot (very possible) isn’t that the obvious difference?

 
Wind is a result of the Earth's rotation, so if you don't take that into effect then the rotation is negligible as both planes are already starting at the rotating speed. Any acceleration and continued acceleration would be equal at that point.
yeah, no

 
I voted different times based on earths rotation - unless I’m misreading (somewhat possible) or I’m an idiot (very possible) isn’t that the obvious difference?
They both take off from an Earth that is already rotating.  So before they take off, they are spinning with the Earth around its axis, as we all do.  Once they they take off, their air speed is relative to the Earth that was already spinning, so the rotation of the Earth does not play a part.

 
They both take off from an Earth that is already rotating.  So before they take off, they are spinning with the Earth around its axis, as we all do.  Once they they take off, their air speed is relative to the Earth that was already spinning, so the rotation of the Earth does not play a part.
Not sure this is how this works. I'm also drunk. 

 
We're gonna need MOP in here to clear this up with some fancy trig equations.
He is especially good with round objects.  Just pictue the earth like a pizza.   The crazy people can picture it round like the crust.  The wise people can picture the earth as flat with yummy tomato sauce and gooey cheese splattered with large chunks of sausage.  The only real question is do we assume the 10" pizza or the 14" pizza?

 
At normal altitudes the rotation of the earth won't make a difference.    At extremely high altitudes planes could begin to leave the atmosphere and then could be affected by the spin.

 
I mean, if we are supposed to ignore everything, then imagine two super-slow houseflies in tiny space suits that launch up in opposite directions from the Moon, with no atmosphere. Then just barely "fly" forward at almost zero speed (but, in reality, pretty much just hover in place). The moon is going to rotate under one of them and come around and that one will get "back" to the starting point faster. 
I don't think we are supposed to ignore everything.  I think by ignoring wind and weather, we are not ignoring an atmosphere but only assuming the atmosphere is moving at the same speed (at least angular speed) as the land beneath it during the duration of the trip.

I think once you make those assumptions, it doesn't matter if we're talking about two planes flying above the equator or two cars driving on a hypothetical track on its surface.  If the two are traveling at the same speed relative to the Earth (and its atmosphere) and traveling the same distance, they will arrive at the same time.

(I think)

 
I don't think we are supposed to ignore everything.  I think by ignoring wind and weather, we are not ignoring an atmosphere but only assuming the atmosphere is moving at the same speed (at least angular speed) as the land beneath it during the duration of the trip.

I think once you make those assumptions, it doesn't matter if we're talking about two planes flying above the equator or two cars driving on a hypothetical track on its surface.  If the two are traveling at the same speed relative to the Earth (and its atmosphere) and traveling the same distance, they will arrive at the same time.

(I think)
I think the rotation of the earth is the significant factor here.

If the Airspeed Indicator for the 2 planes is kept identical, they are flying the same speed, but the earth is rotating below them.

As someone earlier mentioned, the plane flying against the earth's rotation will have the advantage and arrive sooner at the starting point.

There's probably some interesting aspect being missed in this problem, so :popcorn:  for what I'm not thinking of.

 
Why does the earth's rotation not have an influence on how long is the flight from east-west/west-east? originally appeared on Quora: the place to gain and share knowledge, empowering people to learn from others and better understand the world.

Answer by Robert Frost, Instructor and Flight Controller at NASA, on Quora:

Does the Earth’s rotation have an influence on how long it takes to drive from east to west versus driving the same route from west to east? Does it take you a different amount of time to walk across your bedroom from east to west than it does walking from west to east?

Why would you expect the Earth's rotation to influence the length of a flight for an airplane? An airplane sitting on the runway, at the equator, is traveling eastwards at 1000 mph (1600 km/h), just as the ground below it is traveling at that speed. If it wasn't, it would appear to roll backwards at great speed. Once the airplane lifts off of the ground and starts flying, it still has that 1000 mph (1600 km/h), just as the ground does.

If you think that 1000 mph (1600 km/h) disappears, what force do you think took it away? Newton's first law of motion tells us that “…An object in motion continues in motion with the same speed and in the same direction unless acted upon by an unbalanced force.” In order for that motion to go away, a force is needed.

If there were such a force, would it not act upon you if you jumped in the air for a second? If by jumping into the air for a second, you could erase the 1000 mph (1600 km/h) that you have by standing still upon the moving ground, you would land about 1450 ft (450 m) away from where you first jumped. That clearly doesn't happen.

And if there were such a force from the ground that kept you moving forward at 1450 ft/s (450 m/s) when your body wanted to be motionless, wouldn't that exert a hell of a stress on the bottom of your feet?

The Earth rotates. The atmosphere around the Earth rotates with the Earth. Everything on the ground, in the water, or in the air also rotates - with the Earth - at the same speed as the Earth.

What can impact the travel time for east-west vs. west-east are the prevalent winds caused by coriolis effect which in turn arises because of the Earth’s rotation. At some latitudes the prevailing winds are westwards and at other latitudes they are eastward.
https://www.forbes.com/sites/quora/2017/03/31/why-the-earths-rotation-does-not-affect-latitudinal-airplane-travel/#10baffdeddcd

 
The interesting aspect is we are ignoring any physics of the problem with the assumptions and it is just a geometry problem and not really one at that.  

 

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