Question

A tall cylinder contains 20 cm of water. Oil is carefully poured into the cylinder, where it floats on top of the water, until the total liquid depth is 40 cm.

Required:
What is the gauge pressure at the bottom of the cylinder?

Answer 1

Answer:

Pressure, P = 3724 Pa

Explanation:

Given that,

Depth of water, $h_w=20\ cm =0.2\ m$

Depth of oil, $h_o=40-20=20\ cm=0.2\ m$

The density of water, $d_w=1000\ kg/m^3$

The densinty of oil, $d_o=900\ kg/m^3$

We need to find the gauge pressure at the bottom of the cylinder. So, total pressure is equal to :

$P=d_wgh_w+d_ogh_o\\\\P=(d_wh_w+d_oh_o)g\\\\P=(1000\times 0.2+900\times 0.2)\times 9.8\\\\P=3724\ Pa$

So, the gauge pressure at the bottom of the cylinder is 3724 Pa.