The acceleration of a moving body can be found from

The figure shows a speed-time graph of a particle in motion along a constant direction. Three equal intervals of time are shown. In which interval is the average acceleration greatest in magnitude? In which interval is the average speed greatest? Choosing the positive direction as the constant direction of motion,give the signs of $v$ and $a$ in the three intervals. What are the accelerations at the points $A, B, C$ and $D$?

$A$ particle moves along $X$-axis in such a way that its coordinate $x$ varies with time $t$ according to the equation $x = (2 - 5t + 6t^2) \ m$. The initial velocity of the particle is ....... $m/s$.

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

The $x - t$ graph shown in the figure represents:

Why is instantaneous velocity defined?