The acceleration time graph of a particle moving along a straight line is as shown in figure. At what time (in second) the particle acquire its initial velocity?

Explanation

`a=a_(0)t+a_(1), t=0,a=a_(1)=10, a_(1)=10,a=0at t=4`seconds.
`0=+4 a_(0)+10, a_(0)=2.5`
`a=2.5t+10,(dv)/(dt)=-2.5t+10`
`intdv=int(-2.5t+10)dt, v=2.5t^(2)/2+10t+C`
`t=0,C=v_(0), v=-2.5t^(2)/2+10t+v_(0)`
`v=v_(0)-2.5t^(2)/2+10t=0,2.5t^(2)/5=10t`
t=8 seconds.