Suppose a tunnel is dug along a diameter of the earth. A particle is dropped from a point at a distance $h$ directly above the tunnel. The motion of the particle as seen from the earth will be,

The displacement versus time curve for a particle executing SHM is shown in figure. Choose the correct statement(s).

A particle starts from point $x=\frac{-\sqrt{3}}{2}A$ and move towards negative extreme as shown. If the time period of oscillation is $T$, then,

A simple pendulum of length $1 m$ is displaced by an angle $2°$ from its mean position and released from rest. It collides elastically with a wall which is inclined at an angle of $1°$ with vertical on other side of mean. Its time period (in sec) of motion is $\frac{x}{3}$, what is the value of $x$? (Take: $g={\pi }^2$)

Two blocks of mass $30 kg\&60 kg$ are connected to each other with springs in natural length on a smooth ground as shown in figure. An impulse is provided to both blocks in outward direction. The minimum time (in sec) after which the springs are in their maximum elongation position is $\frac{\pi }{n}$, what is the value of $n$?