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

The acceleration $(a)$ - time $(t)$ graph for a body starting from rest is given below. The maximum speed of the body is (in $m/s$)

Acceleration of a particle changes when:

$A$ particle starts from rest. Its acceleration $(a)$ versus time $(t)$ graph is as shown in the figure. The maximum speed of the particle will be (in $m \ s^{-1}$)

The displacement is given by $x = 2t^2 + t + 5$,the acceleration at $t = 2 \ s$ is ......... $m/s^2$.

The acceleration of a particle which moves along the positive $x$-axis varies with its position as shown in the graph. If the velocity of the particle is $0.8 \ m/s$ at $x = 0$,find the velocity of the particle at $x = 1.4 \ m$ (in $m/s$).