A barrel contains a 0.120-m layer of oil floating on water that is 0.250 m deep. The density of the oil is 600 kg/m3. (a) What is the gauge pressure at the oil–water interface? (b) What is the gauge pressure at the bottom of the barrel?

Solution 12E Step 1: Equation for the gauge pressure, P = gh Where, - Density of the liquid g - Acceleration due to gravity h - height of the liquid column Step 2: a) Density of the oil, = 600oilm 3 Acceleration due to gravity, g = 9.8 m/s 2 Height of the oil column, h = 0.250 moil Then, pressure at oil-water interface, P = gh oil oil 3 2 P = 600 kg/m × 9.8 m/s × 0.120 m = 705.6 Pa