Asmall projectile is fired vertically downward into a fluid medium with an initial

Asmall projectile is fired vertically downward into a fluid medium with an initial velocity of 60 m> s. due to the drag resistance of the fluid the projectile experiences a deceleration of a = (-0.4v3) m> s2, where v is in m> s. determine the projectile’s velocity and position 4 s after it is fired!