The displacement of a particle, moving in a straight line, is given by $s = 2{t^2} + 2t + 4$ where $s$ is in metres and $t$ in seconds. The acceleration of the particle is........$ms^{-2}$
$2$
$4$
$6$
$8$
The acceleration (a)-time $(t)$ graph for a particle moving along a straight starting from rest is shown in figure. Which of the following graph is the best representation of variation of its velocity $(v)$ with time $(t)$ ?
A particle moves towards east with velocity $5\, m/s$. After $10$ seconds its direction changes towards north with same velocity. The average acceleration of the particle is