Position time graph of a particle moving along straight line is shown which is in the form of semicircle starting from $t=2$ to $t=8 \,s$. Select correct statement
Velocity of particle between $t=0$ to $t=2 \,s$ is positive
Velocity of particle is opposite to acceleration between $t=2$ to $t=5 \,s$
Velocity of particle is opposite to acceleration between $t=5$ to $t=8 \,s$
Acceleration of particle is positive between $t_1=2 s$ to $t_2=5 \,s$ while it is negative between $t_1=5 \,s$ to $t_2=8 \,s$
For the acceleration-time $(a-t)$ graph shown in figure, the change in velocity of particle from $t=0$ to $t=6 \,s$ is ........ $m / s$
Starting from rest, acceleration of a particle is $a = 2(t - 1).$ The velocity of the particle at $t = 5\,s$ is.........$m/sec$