There is a simple pendulum hanging from the ceiling of a lift. When the lift is standing still,the time period of the pendulum is $T$. If the resultant acceleration becomes $g/4$,then the new time period of the pendulum is: (in $T$)

$A$ simple pendulum is taken to a place where its distance from the Earth's surface is equal to the radius of the Earth. Calculate the time period of small oscillations if the length of the string is $4.0 \ m$. (Take $g = \pi^2 \ m/s^2$ at the surface of the Earth.) (in $s$)

$A$ cylindrical plastic bottle of negligible mass is filled with $310\, ml$ of water and left floating in a pond with still water. If pressed downward slightly and released,it starts performing simple harmonic motion at angular frequency $\omega$. If the radius of the bottle is $2.5\, cm$,then $\omega$ is close to ..... $rad\, s^{-1}$ (density of water $= 10^3\, kg/m^3$).

$A$ string of a pendulum of length $l$ is displaced through $90^{\circ}$ from its vertical and released. Then,the minimum strength of the string needed to withstand the tension as the pendulum passes through its mean position is

''Motion of a simple pendulum from the mean position for small displacement is a simple harmonic motion'' - Explain this statement.

The angular velocity and the amplitude of a simple pendulum are $\omega$ and $a$ respectively. At a displacement $X$ from the mean position,if its kinetic energy is $T$ and potential energy is $V$,then the ratio of $T$ to $V$ is: