Earth is a rotating frame of reference, even then it is considered as inertial frame of reference for all practical purposes. Why ?

Explanation

Earth is revoling around the sun. Thereforce , it possesses centripetal acceleration . Therefore , it should be treated as non inertial frame of reference. However. Value of centripetal acceleration of earth ,
` a = (upsilon^(2))/R = omega^(2) R = ((2 pi)/(T))^(2) R = (4pi^(2)R)/(T^(2)) `
Putting ` R = 1 A .U = 1 .496 xx 10^(11) m , `
and ` T = 365 (1)/(4)` days
`= (1461)/(4) xx 24 xx 60 xx 60 xx sec`
` = 3.16 xx 10^(7) sec`, we get
`a = 4 xx (22)/(7) xx (22)/(7) xx (1.496 xx 10^(11))/((3.16 xx 10^(7) )^(2))`
` = 0.006 m//s^(2)`
which is negligibly small compared to acceleration due to gravity `(g = 9.8 m//s^(2))` hence for terrestrial experiments , earth can be considered as an inertial frame .