A transverse wave is travelling along a string from left to right. The below figure represents the shape of the string at a given instant. $A$, $B$, $C$, $D$, $E$, $F$, $G$ and $H$ are points on the string. At this instant, which of the above points have maximum magnitude of velocity?

The below figure represents the displacement of a particle along the $X$-axis as a function of time. Find the direction of velocity and acceleration of the particle between $O$ and $A$.

The below figure represents the displacement of a particle along the $X$-axis as a function of time. Find the direction of velocity and acceleration of the particle between $A$ and $B$.

The below figure represents the displacement of a particle along the $X$-axis as a function of time. Find the direction of velocity and acceleration of the particle between $C$ and $D$.