For the apparent weight of a body at equator to become zero, the earth should rotate with an angular velocity of
- A. $\sqrt{2g/r}$
- B. $\sqrt{g/r}$
- C. $\sqrt{g/2r}$
- D. $g/r$
Answer: B. $\sqrt{g/r}$
Explanation: Apparent weight $W = m(g - r\omega²)$. For zero weight, $g = r\omega² \Rightarrow \omega = \sqrt{g/r}$.