FIGURE P$8-45$

$8-86$ Water at $15C$ is drained from a large reservoir using two horizontal plastic pipes connected in series. The first pipe is $20m$ long and has a $10-$cm diameter, while the second pipe is $35m$ long and has a $4-cm$ diameter. The water level in the reservoir is $18m$ above the centerline of the pipe. The pipe entrance is sharp$-$edged, and the contraction between the two pipes is sudden. Neglecting the effect of the kinetic energy correction factor, determine the discharge rate of water from the reservoir.