Total pressure at a depth in a fluid

AI Thread Summary
Total pressure at a depth in a fluid typically includes atmospheric pressure for accuracy, but many textbook problems focus solely on fluid pressure due to the minimal contribution of atmospheric pressure. Clarification is advised for course-related questions, as some problems may specify atmospheric pressure while others do not. The atmospheric pressure is roughly equivalent to the pressure at a 10-meter depth in water, so at 20 meters underwater, the total pressure experienced would be three times the normal atmospheric pressure. It is common for total pressure calculations to exclude atmospheric pressure in certain contexts. Understanding this distinction is important for accurate problem-solving in fluid mechanics.
Molly1235
Messages
77
Reaction score
4
Hello,

I would just like some clarification on this...

When you calculate "total" pressure at a depth in a fluid do you have to add on the value for atmospheric pressure??

Thanks,
Molly :-)
 
Physics news on Phys.org
If you want to be very accurate, yes. However the atmospheric pressure adds so little to the pressure due to the fluid that most textbook problems only deal with the fluid pressure. If you are asking about problems for a course, it would be best to ask your teacher.
 
HallsofIvy said:
If you want to be very accurate, yes. However the atmospheric pressure adds so little to the pressure due to the fluid that most textbook problems only deal with the fluid pressure. If you are asking about problems for a course, it would be best to ask your teacher.

Ok, I was just confused because there was this one question from an old book that gave us the value of atmospheric pressure whereas none of the other questions have so I haven't included it but still got the answers right...thank you!:)
 
the atmosphere has the same pressure as 10 meters depth of water, if I remember right. So if you are 20m underwater, then you will experience a pressure of 3 times normal.

edit: after seeing your reply, I guess the 'total pressure' was the total pressure with respect to atmospheric pressure. (i.e. not inlcuding the pressure of the atmosphere). I think this is fairly common.
 
Thread 'Voltmeter readings for this circuit with switches'
TL;DR Summary: I would like to know the voltmeter readings on the two resistors separately in the picture in the following cases , When one of the keys is closed When both of them are opened (Knowing that the battery has negligible internal resistance) My thoughts for the first case , one of them must be 12 volt while the other is 0 The second case we'll I think both voltmeter readings should be 12 volt since they are both parallel to the battery and they involve the key within what the...
Thread 'Trying to understand the logic behind adding vectors with an angle between them'
My initial calculation was to subtract V1 from V2 to show that from the perspective of the second aircraft the first one is -300km/h. So i checked with ChatGPT and it said I cant just subtract them because I have an angle between them. So I dont understand the reasoning of it. Like why should a velocity be dependent on an angle? I was thinking about how it would look like if the planes where parallel to each other, and then how it look like if one is turning away and I dont see it. Since...
Back
Top