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by gandalfu 3532 days ago
Why is the plane going faster? Less resistance from the wind due to the smaller speed difference? I don't believe the air can push the airplane...

Any physicist care to explain?

5 comments

The airplane works by pushing the air and gets a speed relative to the air. If the air is moving, the ground speed will need that speed added.

Ignoring the airplane pushing the air, an airplane can be pushed by wind too.

An airplane on the ground would not be pushed by air, because of friction. If you somehow managed to make an airplane float (without using the engines), this is no longer a factor; quite the reverse. The airplane will be dragged along by the air. "big things can't be pushed by air" is ground-logic, due to friction against the ground.

Not a physicist, but if a plane is flying by 900 km/h compared to the air, and the air is moving by 100 km/h relative to Earth, it can make the plane fly 800 or 1000 km/h relative to Earth, can't it?
If you're moving 20 m/s in a tank of water that's moving along the ground at 2 m/s, your ground speed is 22 m/s.
> I don't believe the air can push the airplane...

Before I reply to you, first tell me if this is some sort of strange form of trolling, or do you really believe that?

No trolling, It seems to me the airplane does not have enough surface area (sail) to be pushed by the wind.

My final conclusion is relative movement, the jet stream is moving at speed X vs the ground and the airplane at speed Y vs the surrounding wind, the airplane moves then at speed X+Y vs the ground.

My question is now, a GPS based speedometer will read X+Y speed. A wind based one will read just X.

I should have asked if the airplane is moving faster vs the surrounding wind.

Have you ever taken a canoe on a river? Did you ever notice you don't much more you have to paddle to go back upstream?