Define Rotation.What is the period of rotation? What are its effects ?

Rotation : The spinning of the Earth on its axis from West to East is called rotation. The Earth takes about 24 hours (23 hours 56 minutes 4 seconds) to complete one rotation. It is also known as daily motion of the Earth. 

Effects : 

(a) Rotation causes days and nights. 

(b) All heavenly bodies like Sun, Moon, planets appear to move from East to West. 

(c) Tides occur regularly twice a day. 

(d) Winds and ocean currents change their directions. 

(e) The four main directions (North, South, East, West) can be determined with the help of rotation. 

(f) We get a measure of time. A day consists of 24 hours – one complete rotation. 

(g) The different times of a day like sunrise, noon, sunset, midnight can be determined due to rotation.