The acceleration,  , of a particle moving in a straight line is given by  ,  where    is the velocity of the particle at any time . The initial velocity of the particle when at origin O is  .

The displacement of the particle from O when its velocity is    is

The acceleration ms¯² of a body moving in a straight line in terms of the velocity ms¯¹ is given by 

Given that    when  , where is the displacement of the body in metres, find the velocity of the body when    (4 marks)