If $v$ is the velocity of a body moving along the $x$-axis,then the acceleration of the body is .........

At any instant,the velocity and acceleration of a particle moving along a straight line are $v$ and $a$. The speed of the particle is increasing if

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

$A$ particle moves along a straight line such that its displacement at any time $t$ is given by $s = (t^3 - 3t^2 + 2) \, m$. The displacement when the acceleration becomes zero is ........ $m$.

What can be the angle between velocity and acceleration for the motion on a straight line? Explain with an example.

The acceleration of a particle which moves along the positive $x$-axis varies with its position as shown in the figure. If the velocity of the particle is $0.8 \,ms^{-1}$ at $x=0$, then its velocity at $x=1.4 \,m$ is (in $ms^{-1}$)