Figure shows the graph of $x$-coordinate of a particle moving along $x$-axis as a function of time. Average velocity during $t=0$ to $6 \,s$ and instantaneous velocity at $t=3 \,s$ respectively, will be

Acceleration versus velocity graph of a particle moving in a straight line starting from  rest is as shown in figure. The corresponding velocity-time graph would be

Two buses $P$ and $Q$ start from a point at the same time and move in a straight line and their positions are represented by $X _{ P }( t )=\alpha t +\beta t ^{2}$ and $X _{ Q }( t )= ft - t ^{2}$. At what time, both the buses have same velocity $?$

A ball is thrown vertically upwards. Which of the following graph/graphs represent velocity-time graph of the ball during its flight (air resistance is neglected)

For a particle projected vertically upwards under gravity travels equal distance during $5^{th}$ and $6^{th}$ second of its motion. Find its projection speed........$m/s$ $(g = 9.8\,m/s^2)$

Let $v$ and $a$ denote the velocity and acceleration respectively of a body