For the displacement-time graph shown in the figure,the ratio of the magnitudes of the (constant) speeds during the first two seconds and the next four seconds is

The following figures show velocity $v$ versus time $t$ curves. But only some of these can be realized in a particle. These are:

The velocity-time graph of a body moving in a straight line is shown in the figure. The ratio of displacement to distance travelled by the body in time $0$ to $10 \text{ s}$ is

The velocity-displacement graph of a particle is shown in the figure. The acceleration-displacement graph of the same particle is represented by:

Two cars $A$ and $B$ start from a point at the same time in a straight line and their positions are represented by $R_{A}(t) = at + bt^2$ and $R_{B}(t) = xt - t^2$. At what time do the cars have the same velocity?

The acceleration-time graph of a particle moving along a straight line is shown. At what time does the particle acquire its initial velocity? (in $s$)