Q 11-04-006NEETNEET 2024Top questionEasy
A bob is whirled in a horizontal plane by means of a string with an initial speed of $\omega$ rpm. The tension in the string is $T$. If speed becomes $2\omega$ while keeping the same radius, the tension in the string becomes :
Answer: (D) $4T$
The tension provides the centripetal force: $T = m\omega^2 r$.
With the same radius, $T \propto \omega^2$. Doubling $\omega$ gives
$$T' = 4T$$
Solution by Sreeraj P, M.Sc Physics