From the velocity-time graph, given in figure of a particle moving in a straight line, one can conclude that:

  

The velocity-time graph of a particle moving in a straight line is shown in the figure. The acceleration of the particle at $t=9 \mathrm{s}$ is-

The $v-t$ graph of a body is given in figure. The maximum acceleration in $\mathrm{m} {\mathrm{s}}^{-2}$ is

The displacement-time graph of a body is shown in the figure.

The velocity-time graph of the motion of the body will be

The acceleration will be positive in

The graph shown in the figure below describes the motion of a ball rebounding from a horizontal surface being released from a point above the surface. Assume that the ball collides each time with the floor inelastically. The quantity represented on the $y$-axis is the ball's (take upward direction as positive)