$A$ tunnel has been dug through the centre of the Earth and a ball is released in it. It will reach the other end of the tunnel after:

The average speed of the bob of a simple pendulum oscillating with a small amplitude $A$ and time period $T$ is

$A$ simple pendulum of length $L$ has mass $m$ and it oscillates freely with amplitude $A$. At the extreme position,its potential energy is ($g =$ acceleration due to gravity).

Identify the correct statement.

$A$ pendulum clock is placed inside an elevator. Under what condition does it show the correct time?

$A$ coin is placed on a horizontal plate. The plate performs $S.H.M.$ vertically with an angular frequency $\omega$. The amplitude $A$ of oscillations is gradually increased. The coin will lose contact with the plate for the first time when the amplitude is ($g =$ acceleration due to gravity).