An object is vertically thrown upwards. Then the displacement-time graph for the motion is as shown in

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)

The acceleration versus time graph of a particle is shown in the figure. The respective $v-t$ graph of the particle is

The displacement-time graph of a moving particle with constant acceleration is shown in the figure. The velocity-time graph is given by

The acceleration versus time graph of a particle moving in a straight line is shown in the figure. The velocity-time graph of the particle would be

The acceleration-time graph of a particle moving along a straight line is as shown in figure. At what time the particle acquires its initial velocity?