To determine the pressure difference between positions 1 and 2 in a pipe using a differential manometer filled with water, we need to apply the principles of fluid mechanics, specifically using the hydrostatic pressure difference.

Given Data:

• Height difference at position 1: $h_1 = 570 \, \text{mm} = 0.570 \, \text{m}$
• Height difference at position 2: $h_2 = 350 \, \text{mm} = 0.350 \, \text{m}$
• Relative density of kerosene: ( \text{RD}_{\text{kerosene}} = 0.78 \