Bernoulli Eqn: Gauge vs Atm Pressure?

[Bassel]

why is when working with Bernoulli equation the absolute pressure that we are NOT looking for has a gauge pressure = 0 and only atmospheric pressure while the one we are looking for has both? is this a rule somehow ?

 

[tiny-tim]

Hi Bassel!

I don't understand.

Can you give an example? ​

 

[Bassel]

the last part of the problem

the last part of the problem by taking the absolute pressure of the right side equal to the atmospheric pressure only by taking the gauge pressure there as 0 while in the left part we are asked to find the gauge pressure. how come one has no gauge and the other has

 

[Bassel]

thats the solution

that was the solution. the last part when we applied the equation and said the gauge pressure in the right side is 0 confused me

 

[tiny-tim]

the question says that the water on the right goes out into the atmosphere

so it is at atmospheric pressure, ie the gauge pressure is 0