Pressure and Bernoulli's relationship?

Question

Anybody who knows about Bernoulli's equation will know that as the area of a tube narrows, the flow velocity must increase. If no other force acts on the fluid, the pressure at the tube with a wider diameter must be greater than the presure at the point of the tube with a smaller diamter.

I dont understand why is the pressure at the wider diamter tube section higher compared to the one at the smaller diameter. I thought that if the force of the fluid is spread out over a larger area, the pressure would fall?

Please explain! This question has been bugging me for a long time!

Answer 1

Bernoulli equation attempts to explian that the toal energy is same at any point in a fluid
Consider a fluid moving in a pipe with varying cross section.
As the throughput (or flow) is constant the liquid has to move fast (or with higher velocity) at the reduced cross sectional area because velcoity X area = throughput (flow given in m3/sec or vol/sec)
Now kinectic energy is (mv^2) /2 hence some other energy has to decrease to compensate for the reduction of energy. or the sum of energies will change.Assumping other energy (friction loss or potential energy) remains same the pressure energy decreases.

(When you say more area less pressure are you mixing up the subject with boyle gas for ideal gas which talks about volume and pressure ??? )