The curvature of the football field

[Wool]

I decided to calculate the curvature of a football field. Those. when the field is leveled by a laser level, and the Earth is round
This means that the center of the field should be lower than the edges. I figured it out in my head - it turned out to be 2-3 cm! This is the water that will flow into the center.

And now I calculated on the calculator using the cosine
I determined how many kilometers are in one degree. I divided the circumference of the Earth into 360 degrees: 40,000/360 = 111 km approximately.
I determined the angle of a football field, from the edge to the center: 0.06 km/111, then took its cosine.
Well, multiplied the cosine by 6,300,000 m (radius of the Earth). I got a 0.3 mm depression
Have I made a mistake anywhere?

[I worship]

https://i.postimg.cc/VvFQpZ9T/1529579364185872571.jpg
Российская порно-сборная по футболу, cоставленная неизвестным тренером. Ну, если участие в ней Кристал Болйд, Марины Висконти, Джины Джерсон и Елены Кошки несомненно, то отсутствие в ХХХ-составе Kayla Green, Henessy и самой горячей студентки МГИМО Ally Brielsen ставит под сомнение тренерскую компетентность. А вы бы кого добавили?

[bot458]

I decided to calculate the curvature of a football field. Those. when the field is leveled by a laser level, and the Earth is round
This means that the center of the field should be lower than the edges. I figured it out in my head - it turned out to be 2-3 cm! This is the water that will flow into the center.
...

Gee, I just forgot about the rotation of the earth. So the water will fly from the center of the field into space, yeah

[RANGE_]

So the field is not crooked, but is specially made with a slope and also levels it out.

scale_720-1.jpeg

scale_720.jpeg

The permissible slope angle of the base surface is from 3 mm to 6 mm per 1 linear meter.
The height difference on the base surface is no more than 9 mm per 3-meter rail.
The density of the base of a football field is the value of the dynamic modulus of deformation (Evd), measured on the surface of the football field ≥ 120 MN/m2.

And how to calculate without accurate data?
I didn’t understand the essence of such a pen))

[Wool]

And how to calculate without accurate data?
I don’t understand the essence of such a pen))

Why without accurate data? The length of the field is known (100-120 m), the radius of the Earth is known.
It was Perelman who said that if you build a tunnel in a straight line, then in its center there will be a puddle of rainwater.
Therefore, tunnels are made with slopes from center, like above in the picture.

https://allforchildren.ru/scibooks/img/perelman2-43.gif

[Wool]

Why did I get 2-3 cm in my head? About 10 years ago I thought that from a distance of 120 km you couldn’t see a mountain 450 m high, it would be beyond the horizon.
Well, I took the simple proportion but it doesn’t work here. The farther you go, the more the earth “bends.”
Well, in general, what is the conclusion here, with dimensions of hundreds of meters, the curvature of the Earth does not matter, about a millimeter. Only with kilometers: a bridge, a tunnel, a runway need to be taken into account here.