Why is velocity = 0 in Bernoulli equation?

A gasoline storage tank drains by gravity to a tank truck; see the drawing. The pipe line between the tank and the truck is 100m of 0.1m diameter commercial steel pipe. The properties of gasoline are given as, density =720 kg/m3, dynamic viscosity =0.0006kg/m.s. Both tank and truck are open to the atmosphere, and the level in the tank is 10m above the level in the truck. What is the volumetric flow rate of the gasoline? P+hyh+gz=mNff=gz0z=04f(VhV=4fM(7)0=3.13mil