The acceleration of the body is determined by differentiating the velocity, and velocity by differentiating the displacement. By doing the reverse, we integrate the acceleration to get the velocity and integrate the velocity to get the displacement.
velocity = 20v^-3 and displacement = (20/3)v^-2
Substituting the value of v,
velocity = 20/(2 m/s)^3 = 2.5 m/s
displacement = 20/3 / (2m/s)² = 5/3 m