Monica stepped outside and began to think how fast she is moving even when she is standing still.

Question

Assume that the earth is a sphere with a radius of 3960 miles and Monica is at a latitude of 13∘N.

What is Monica's speed due solely to the rotation of the earth in miles per hour?

Answer 1

the radius of the earth at that latitude is

r = 3960 cos13°

so the speed there is 2πr/24 mi/hr