cv = 0.82 cc = 1.00 c = 0.82,
Q = 0.82Ω √(2gh).
It is easy to see from the equations that the pressure p at EF is less than atmospheric pressure. Eliminating v1, we get
(pa − p)/G = 3⁄4 h nearly;
(3)
or
p = pa − 3⁄4 Gh ℔ per sq. ft.
If a pipe connected with a reservoir on a lower level is introduced into the mouthpiece at the part where the contraction is formed (fig. 59), the water will rise in this pipe to a height
KL = (pa − p) / G = 3⁄4 h nearly.
If the distance X is less than this, the water from the lower reservoir will be forced continuously into the jet by the atmospheric pressure, and discharged with it. This is the crudest form of a kind of pump known as the jet pump.