The acceleration-time graph for a body is shown in the graph. Which of the following  graphs would probably represent velocity of the body plotted against time:-

The diagram shows the variation of $1 / v$ (where, $v$ is velocity of the particle) with respect to time. At time $t=3\,s$ using the details given in the graph, the instantaneous acceleration will be equal to $...........m/s^{2}$

A particle moves a distance $x$ in time $t$ according to equation $x = (t + 5)^{-1}$ The  acceleration of particle is proportional to 

What will be change in speed of moving object if both speed and acceleration are positive or negative ?

The distance-time graph of a particle at time $t$ makes angle $45^{\circ}$ with the time axis. After one second, it makes angle $60^{\circ}$ with the time axis. What is the average acceleration of the particle?

Draw the $x\to t$ graphs for positive, negative and zero acceleration.