Question

How and why does Earth spin?

Answer 1

Hint: Earth's rotation or spin is that the rotation of planet Earth around its own axis. Earth rotates eastward, in pro grade motion. As viewed from the north-pole star Polaris, Earth turns counterclockwise.

Complete answer:
Imagine a line passing through the middle of Earth that goes through both the North Pole and therefore the South Pole. This imaginary line is named an axis. Earth spins around its axis, even as a top spins around its spindle. This spinning movement is called Earth’s rotation. At an equivalent time that the world spins on its axis, it also orbits, or revolves around the Sun. This movement is called the revolution.
A pendulum set in motion won't change its motion then the direction of its swinging shouldn't change. However, Foucault observed that his pendulum did seem to vary direction. Since he knew that the pendulum couldn't change its motion, he concluded that the world underneath the pendulum was moving.
 An observer in space will see that Earth requires 23 hours, 56 minutes, and 4 seconds to form one complete rotation on its axis. But because Earth moves round the Sun at an equivalent time that it's rotating, the earth must turn just a touch bit more to succeed in an equivalent place relative to the Sun. Hence the length of each day on Earth is really 24 hours. At the equator, the world rotates at a speed of about 1,700 km per hour, but at the poles the movement speed is almost nothing.

Note:
Our planets have continued spinning due to inertia. Within the vacuum of space, spinning objects maintain their momentum and direct their spin because no external forces are applied to prevent them. And so, the planet and therefore the remainder of the planets in our system keep spinning.