Which one of the following represents the displacement-time graph of two objects $A$ and $B$ moving with zero relative velocity?

$A$ particle of unit mass undergoes one-dimensional motion such that its velocity varies according to $v(x) = \beta x^{-2n}$,where $\beta$ and $n$ are constants and $x$ is the position of the particle. The acceleration of the particle as a function of $x$ is given by:

The displacement-time graphs of two moving particles make angles of $30^{\circ}$ and $45^{\circ}$ with the time-axis as shown in the figure. The ratio of their respective velocities is:

The figure shows a velocity-time graph of a particle moving along a straight line. The particle comes to rest at $t = \dots \text{sec}$.

The figure shows the $x-t$ plot of a particle in one-dimensional motion. Three different equal intervals of time are shown. In which interval is the average speed greatest,and in which is it the least? Give the sign of average velocity for each interval.

Match Column-$I$ with Column-$II$ based on the distance-time $(d-t)$ graphs provided in the image.

$(1)$ Velocity decreases	$(a)$ Linear graph (constant slope)
$(2)$ Velocity increases	$(b)$ Concave up graph (increasing slope)
$(3)$ Velocity is constant	$(c)$ Concave down graph (decreasing slope)