The earth's radius is 6.37×106m; it rotates once every 24 hours. What is the earth's angular speed? Viewed from a point above the North Pole, is the angular velocity negative and positive? What is the speed of a point on the equator? What is the speed of a point on the earth's surface halfway between the pole and the equator? (Hint: what is the radius of the circle in which the point moves?)