The periodic time of a simple pendulum is $T_1$. Now if the point of suspension of this pendulum starts moving along the vertical direction according to the equation $y = kt^2$, the periodic time of the pendulum becomes $T_2$ . Therefore, $ {T_1 ^2 \over T_2^2 } = .........( k =1 m/s^2 and g = 10 m/s^2 ) $
$ here y = kt^2 $ $ \therefore { dy \over dt } = 2 kt \Rightarrow { d^2 y \over dt^2 } = 2k = 2 ms^{-2} $ $ \therefore the point of support in \;moving\; upwards with\; an acceleration\; of 2 m/s^2 $ $ \therefore effective acceleration g' = g + a = 12 m/s^2 $ $ now \;T_1 = 2 \pi \sqrt { l \over g } and\; T_2 = 2 \pi \sqrt { l \over g } $