The time required for a fluid particle on the axis to travel from the inlet to the exit plane of the nozzle is

Question

In a steady flow through a nozzle, the flow velocity on the nozzle axis is given by u = u₀ (1+3x/L), where x is the distance along the axis of the nozzle from its inlet plane and L is the length of the nozzle. The time required for a fluid particle on the axis to travel from the inlet to the exit plane of the nozzle is            

      (a)  $\frac{L}{u_{o}}$                                                                 (b) $\frac{L}{3u_{o}}In4$ 

      (c) $\frac{L}{4u_{o}}$                                                               (d)$\frac{L}{2.5u_{o}}$