Question

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 600kg/m3. (a) What is the gauge pressure at the oil - water interface ? (b) what is the gauge pressure at the bottom of the barrel ?

Answer 1

PART (a)Gague pressure at the oil−water interface will be only due to the depth of oilPinterface = hρg = 0.12×9.81×600 = 706.32 Pa
PART (b)Gauge pressure at the bottom will be due to both the oil and the waterPbottom = h1ρ1g + h2ρ2g              = 9.81×(0.12×600 + 0.25×1000)  =3158.82 Pa