# Pressure of fluid

1. Jun 24, 2012

### moatasim23

According to Bernoulli eq Pressure of a fluid in a vertical pipe is lower where area is small.But from General formula P=F/A.Pressure should be higher.Isnt it a contradiction?

2. Jun 24, 2012

### andytinker

Some fluids have minimal compression, like water. Two vertical pipes joined at the bottom with one smaller than the other would have movement.

3. Jun 24, 2012

### moatasim23

Sorry I didnt get the point.Im assuming an incompressible fluid.

4. Jun 24, 2012

### moatasim23

????

5. Jun 24, 2012

### HallsofIvy

It would be if F were a constant. In Bernoulli's equation it is the fluid flow that is constant, not the force

6. Jun 24, 2012

### moatasim23

Why F is not constant?On which factors does F depends here?

7. Jun 25, 2012

### moatasim23

Is this explanation correct?
There are two types of pressures :
1)Static pressure
2)Dynamic pressure
In bernoullis eq we are talking about Dynamic pressure which increases or decreases wd fluid speed.

8. Jun 25, 2012

### andytinker

With minimal compression, the fluid doesn't follow PV=P1V1. If you have flow from a small section to large the pressure is lower, if its a compressible fluid that gets changed to velocity F=mv2, if its not velocity slows down.

I think

9. Jun 25, 2012