The acceleration of a moving body can be found from

Which of the following curves does not represent motion in one dimension?

The figure shows the displacement of a particle moving along the $X-$axis as a function of time. The force acting on the particle is zero in the region:

$A$ particle of mass $m$ is constrained to move on the $x$-axis. $A$ force $F$ acts on the particle. $F$ always points toward the position labeled $E$. For example,when the particle is to the left of $E$,$F$ points to the right. The magnitude of $F$ is a constant $F_0$ except at point $E$ where it is zero. The system is horizontal. $F$ is the net force acting on the particle. The particle is displaced a distance $A$ towards the left from the equilibrium position $E$ and released from rest at $t = 0$. The velocity-time graph of the particle is:

An object is moving with variable speed,then

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 $t = 0$ to $t = 8 \ s$ is: