Task about Vladivostok to grind your brains

Who proved that the Earth is round? It is widely believed that this was done by the famous Spanish navigator Christopher Columbus. In fact, Greek scientists have proved the sphericality of the earth almost 2 thousand years before its birth.



In the IV century BC, Aristotle pointed out that during lunar eclipses, the shadow of the Earth on the surface of our natural satellite is bent and has the shape of a disk. And 100 years later, the mathematician and astronomer Erastofen, comparing the length of the shadow from the stick on the day of the summer solstice in Alexandria and Siena, was able to calculate with amazing accuracy the length of the circumference of the Earth.



GettyImages is all the more surprising that in our age of interplanetary flight, the idea of a flat Earth is rapidly gaining popularity. Its supporters are constantly looking for new arguments. For example, recently in the Network became popular funny question about the plane. As they say, checkmate, gentlemen of the "ballers"! If the earth is round and rotating, how is it possible?

So, it's time to refresh the memory of the school physics course. You will need it to answer the question from Facebook, which we provide without bills. Everyone knows that the Earth is supposedly rotating at a speed of 1600 km/h at the equator, counterclockwise.



At the latitude of Vladivostok, let it be 1300 km / h. I sometimes flew to Moscow (albeit 10,000 km for simplicity). On a good Boing, which has a speed of about 1000 km / h, from Vladivostok to Moscow about 10 hours there and 10 hours back.



Yes, it is, on a flat earth, so it is!! Nobody's going anywhere!!! And if the Earth is a ball, then, taking into account the rotation of the Earth 1300 km / h counterclockwise, I must fly to Moscow: 1300 km / h (the speed of the Earth) + 1000 km / h (the speed of the aircraft) = 2300 km / h the total speed, therefore 10 000 km to Moscow I will overcome in about 4 hours and 15 minutes!!! And from Moscow to Vladivostok on a spherical supposedly Earth I will never fly, because the speed of the aircraft is 300 km / h less than the speed of the Earth!!!! ?

How does the author of the question get to Vladivostok? Physics answers the question this way: due to the attraction and force of friction The planet with the atmosphere rotates as a whole.. And it is easiest to prove this by imagining the opposite situation: the atmosphere stands still, and the Earth under it rotates at a speed of 1600 km / h (at the equator).



In this case, we would always feel a hurricane blowing in only one direction of crushing force. And more: it would be enough to jump and hover for a second in the air to move about 360 (!) meters. Need Sochi? I jumped for hours and I'm done! But that's not happening, is it? Otherwise, cars, planes and other high-speed transport would not be necessary.

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In short, if you are in the Earth’s gravitational zone (about 1000 km from the surface), you continue to rotate with the atmosphere and the planet, although subjectively you seem stationary. Like, for example, a train passenger who calmly walks on the car to a restaurant, despite the fact that the train is rushing at a speed of 100 km / h in the opposite direction. Therefore, the author of the question can safely fly to Vladivostok, despite the rotation of the Earth, in which he does not believe.

If you liked this problem, pay attention to the “Entertaining Physics” by Yakov Perelman. On each page, the reader can make a real discovery, which teaches to think freely and creatively.

The article and the preview used photos.