It is said that rotation and speed are zero at the poles because the maximum speed of rotation is in the Ecuador, being of 1666 kilometers per hour.
The rotation movement is performed by the earth when rotating on its axis. The earth has two poles: the North Pole and the South Pole and from the physical point of view are studied as points.
Since a point can not undergo a rotation, it is affirmed that there is no rotation. The velocity of a particle located on a sphere may vary depending on the distance it has from the poles.
As we move away from this point towards the poles, this velocity goes down to zero at the poles, which defines the nullity of the rotation.
Another way to define this phenomenon is through the assertion that a point has no space, so it can not rotate.
Geographical poles
Geographic poles are the two points that coincide with the axes of rotation of the earth. They are established as the North Pole and the South Pole.
The poles are the point of convergence of all meridians that do not have geographic length.
North Pole
This is located in a geographical latitude of 90 degrees with respect to the north of the Ecuador. It is above the Arctic Ocean, completely covered by ice.
South Pole
Its location is at a geographical latitude of 90 degrees south of Ecuador. Its marker changes position annually, since, being on a glacier, moves 10 meters each year, so it must be repositioned.
Characteristics of earth rotation
Turn on herself.
-The direction of the movement is the reverse of the clock.
-It lasts for 23 hours, 56 minutes and 4.09 seconds.
-The radius of rotation will decrease proportionally according to its proximity to the poles.
4 Effects of Rotating Motion
1. Sunrise and Sunset
Because the earth rotates continuously on its axis, you can see the sun appear on the east or east, and it is hidden by the west or the west.
What we know as day and night is generated as a consequence of the angle that the planet has in relation to the sun, which illuminates the half of the globe while the other half is in darkness.
2. Widening of the equator
The high velocities that reach the earth during its rotation, causes a centrifugal force that produces a widening of the sphere in its center, in the Ecuador. This gives a flattened appearance to the ground at its poles.
3. Coriolis Effect
This effect is a consequence of centrifugal force. Winds generated and ocean currents move in the opposite direction to the hemispheres.
4. Time zones
The hours of the day are defined directly by the location of the sun. The earth, being a sphere, does not receive direct light uniformly in all its points.
This has generated the creation of different time zones that use as a reference the angle of the earth with respect to the sun.
References
- "Rotation movement - Wikipedia, the free encyclopedia." en.wikipedia.org . Consulted on September 16, 2017.
- "Center and axis of instant rotation - Wikipedia, the free encyclopedia." en.wikipedia.org . Consulted on September 16, 2017.
- "Rotation movement - Wikipedia, the free encyclopedia." en.wikipedia.org . Consulted on September 16, 2017.
- "Earth axis - Wikipedia, the free encyclopedia." en.wikipedia.org . Consulted on September 16, 2017.
- "Geographical pole - Wikipedia, the free encyclopedia." en.wikipedia.org . Consulted on September 16, 2017.