A barrel contains 0.130-m layer of oil floating on water that is 0.290 m deep. The density of the oil is 610 kg/m3
What is the gauge pressure at the bottom of the barrel?
P [/B]= ρ(g)(h)
The Attempt at a Solution
I found the pressure of the oil which is 777 Pa by 610kg/m^3(9.8)(0.130m)
for this one I know I have to add the 777 Pa, but I messed up on the height. I used 0.16 by taking the difference of 0.290m-0.130m = 0.16 m and used that height to multiply to the 1000kg/m^3(9.8)(0.130m)
Can someone explain to me why it's not 0.16m? Does that part of the barrel only take into consideration the pressure of water?