(a) Explain the following terms:
1.rotation of the earth;
2.revolution of the earth;
(b) Outline three effects of the revolution of the earth
1.Earth’s rotation is the rotation of planet Earth around its own axis. Earth rotates eastward, in prograde motion. As viewed from the north pole star Polaris, Earth turns counterclockwise.
2.For Earth to make one complete revolution around the Sun takes 365.24 days. This amount of time is the definition of one year. The gravitational pull of the Sun keeps Earth and the other planets in orbit around the star.
3.An equinox is commonly regarded as the instant of time when the plane of Earth’s equator passes through the geometric center of the Sun’s disk. This occurs twice each year, around 20 March and 23 September. In other words, it is the moment at which the center of the visible Sun is directly above the equator.
(b)Effects of Earth’s revolution include the seasons and variation in the length of days and nights. In addition to revolution, the tilt of Earth’s axis relative to its plane of orbit has a profound effect on Earth. At almost any given time, one hemisphere is tilted toward the sun, as the other is tilted away.