A stone tied to 180 cm long string at its end is making 28 revolutions in horizontal circle in every minute. The magnitude of acceleration of stone…

A stone tied to $\displaystyle 180$ cm long string at its end is making $\displaystyle 28$ revolutions in horizontal circle in every minute. The magnitude of acceleration of stone is $\displaystyle \frac{1936}{x} m s^{-2}$. The value of $\displaystyle x$ $\displaystyle \_\_\_\_$. (Take $\displaystyle \pi=\frac{22}{7}$ )