Where does the A₂² come from in the problem on the last line? The 2nd picture is me trying to solve the problem to derive at the final answer as in the box.

According to Bernoulli's equation, P, + + Pv? + Pgh, = P2 + + PV2 + pghz We assume, P, = Pz , hi = 0, h2= h thus, the equation will condense into; 2 PV . 2 = -- PV2 + Pgh V 2 = V/2 + 2gh From continuity equation; A, VI = Az Vz AIVI A 2 Equating 1 Where does the A2 ^2 come = AVIT + 2gh from? Az Hence, 2gh Az A 2 - AZ2 AIVI 2 1 Az +agh 2 2 A = 2gh