Why is the speed of rotation of Earth decrease at the poles?
Answers
Answer:
The speed of Earth's rotation does not vary significantly. (Usually less than a second in 365 days or so.) It rotates once per day. That's 1 rpd.
What you are referring to is the apparent surface velocity. The distance around the world at the equator is 24,902 miles. So the surface, at the equator, is moving 24902/24 miles per day. Or 1,037.58 mph. This is only at the equator, the distance around the Earth at different latitudes varies to zero at the poles. For instance I live near the 40th latitude. Equator circumference times cosine (40) equals 19,076 divided by 24 equals 794.8 miles per hour surface speed.
I said surface speed, but because of friction, everything moves along with the Earth. The air, the clouds, birds flying, even airplanes, and the entire atmosphere.