Variation of pressure with depth in a fluid with unifrom density (equation of hydrostatic equilibrium) (11-8)
Question 1 of 5
Question
Pressure at a second, lower point in the fluid
{"title":"Pressure at a certain point in a fluid at rest","description":"Wrong","type":"incorrect","color":"#99CCFF","code":"[{\"shape\":\"poly\",\"coords\":\"82,133\"},{\"shape\":\"rect\",\"coords\":\"91,20,126,64\"}]"} {"title":"Density of the fluid (same at all points in the fluid)","description":"Incorrect","type":"incorrect","color":"#ffcc00","code":"[{\"shape\":\"rect\",\"coords\":\"118,11,119,13\"},{\"shape\":\"rect\",\"coords\":\"205,18,241,68\"}]"} {"title":"Acceleration due to gravity","description":"Wrong","type":"incorrect","color":"#333300","code":"[{\"shape\":\"poly\",\"coords\":\"113,132\"},{\"shape\":\"rect\",\"coords\":\"195,33,199,34\"},{\"shape\":\"poly\",\"coords\":\"132,99\"},{\"shape\":\"rect\",\"coords\":\"242,20,269,65\"}]"} {"title":"Depth of the second point where the pressure is p below the point where the pressure is p sub 0","description":"Incorrect","type":"incorrect","color":"#000080","code":"[{\"shape\":\"rect\",\"coords\":\"267,7,301,55\"}]"} {"title":"Pressure at a second, lower point in the fluid","description":"Correct!","type":"correct","color":"#333333","code":"[{\"shape\":\"rect\",\"coords\":\"1,20,34,67\"}]"}
Review
The pressure at the bottom of an imaginary box is greater than the pressure at the top of the box. Furthermore, the box is just an imaginary construct, so the real meaning of Equation 11-7 is as follows: At any two points in the fluid with vertical separation d, the pressure at the lower point is greater than the pressure at the upper point by an amount ρgd. In particular, let p0 be the pressure at the upper point (Figure 11-6). Then the pressure p at a point a distance d below the upper point is:
Equation 11-8 must be satisfied for a fluid to remain at rest, so this is also called the equation of hydrostatic equilibrium.