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# Rotation of earth

What is the velocity of earth rotation at poles? 6std social

gurpreet

Good question...made me look up geography concepts again.
It seems we take 24 hours to make one rotation...at the speed of 1000 miles per hour.
But it seems that the earth hardly moves at the poles because of the small surface area.

gurpreet

The shape of the Earth is not a perfect sphere, but an oblate spheroid. The reason for its oblate spheroid shape shall not be discussed here. For the purpose of studying the rotational speed, we the Earth’s shape can be approximated to a sphere.

Circumference of Earth at the Equator =40,000 km

The time taken for one rotation = 24 h

Speed of rotation at the Equator = (40,000 /24) km/h

=1666.67 km/h

Circumference of Earth at the latitude of 40⁰ N = 30, 600 km

Time taken for one rotation = 24 h

Speed of rotation at 40⁰ N = (30,600/24) km/h

= 1,275 km/h

At the poles, the latitude is 90⁰ and radius is zero

Circumference at the Poles = 0 km

Hence, Speed of Rotation at the poles is zero

Note: Clarification on using the term Speed instead of Velocity

There is no need for direction as we are only interested in the speed of rotation. So, the term speed is more appropriate than velocity.