Question

Assertion: If earth suddenly stops rotating about its axis, then the value of acceleration due to gravity will become the same at all the places on the surface of the earth.
[Assume earth as a perfect sphere]
Reason: The value of acceleration due to gravity is independent of rotation of the earth
A- Both assertion and reason are correct and reason is the correct explanation for assertion
B- Both assertion and reason are correct but the reason is not correct explanation for assertion
C- assertion is correct but reason is incorrect
D- assertion is incorrect but reason is correct

Answer 1

Hint: Earth rotates about its own axis and also it goes around the sun in an elliptical orbit. Earth is not a perfect sphere in shape. Because of the force that acts on it when Earth rotates, the North and South Poles are slightly flat. The occurrence of days and the night is attributed to the rotation of the earth.

Complete step by step answer: The earth rotates about a line, which connects the north pole with the south pole and is called the axis of rotation or the polar axis. So, it is clear that earth rotates about its polar axis.
The value of acceleration due to gravity is governed by the equation:\[g'=g-{{\omega }^{2}}R{{\cos }^{2}}\zeta \]
Here R is the radius of the earth and w is the angular velocity of the earth. Now if earth stops rotating then angular velocity becomes zero and thus g’=g. Thus, the first statement is correct. We have seen that the value of acceleration due to gravity is dependent on rotation of the earth. So, the second statement is incorrect.

Thus, the correct option is (C)

Note: The earth rotates counterclockwise always as viewed from the north pole. Drifting and wobbling takes place when the earth rotates on its spin axis it drifts and wobbles. These spin-axis movements are scientifically referred to as polar motion.