How much work W is done per unit volume on the water going from the upper section to the

lower section?

W $=$

$($iv$)$ Water will vaporize at room temperature if its pressure is reduced below approximately Patm$/40.$

If the lower part of the pipe spills out into an open$-$air pool, then what is the maximum value for

hmax above which the water in the upper pipe would start to vaporize $($cavitate$)?$

hmax $=$

$10$