∴ z1 + v12/2g = z2 + v22/2g − (p1/G1) logε (p1/p2),
(2)
or, neglecting the difference of level,
(v22 − v12) / 2g = (p1/G1) logε (p1/p2).
(2a)
Similarly, if the expansion is adiabatic (eq. 2a, § 61),
z1 + p1/G1 + v12/2g = z2 + p2/G2 + v22/2g − (p1/G1) {1/(γ − 1) } {1 − (p2/p1)(γ−1)/γ};
(3)
or, neglecting the difference of level,
(v22 − v12)/2g = (p1/G1) [1 + 1/(γ − 1) {1 − (p2/p1)(γ−1)/γ)} ] − p2/G2.