Question

The radial clearance between a plunger and the walls of a drum is 0.075 mm, the
length of the plunger is 250 mm and its diameter 100 mm. There is a difference in
pressure of the water on the two ends of the plunger of 207.5 kN/m

Answer 1

$p_r = \rho gh_f = 1000\times 9.81 \times 0.075 =735.75 Pa$