For a pearson not telling anything about yourself you tell a lot whats wrong with others. Is this doing it right in your opinion?Steve R:
Physics
- Thread starter richarddean
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Steve R:
the PADI DM course usually requires the student to reqd the section first and complete a series of questions/problems before attending class
would be glad to help but I only do Imperial - too old to change, no matter that it's probably easioer and the rest of the worlkd does it
richarddean:
38.8 liters (+/-) will get you your 40 kg of buoyancy. Some of the previous posters can split hairs all they want, but it's a simple conversion I learned in my first week in naval architecture school. Regarding the weight of seawater, 64.2 lb/cu.ft. is the recognized standard. Liters and cubic feet are both simple expressions of volume, and can be easily converted; likewise pounds to kilos and vice versa.
UP4AIR
Contributor
Does this mean that if I go in the water with an 80 cu/ft tank south of the longitudinal equator and a hose of 5' wrapped to my right up around my neck and down across my left shoulder at 1300 hrs with the sun at the 45 deg meridian ...that I'm going to run out of air and DIE?
UP4AIR:Does this mean that if I go in the water with an 80 cu/ft tank south of the longitudinal equator and a hose of 5' wrapped to my right up around my neck and down across my left shoulder at 1300 hrs with the sun at the 45 deg meridian ...that I'm going to run out of air and DIE?
Only if it's an alternate leap Tuesday and you keep you left eye shut for 14 seconds ...
dumpsterDiver
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When I took my PADI final instructor exam a number of years ago, there was a very similar question and the responses were multiple choice. I determined that NONE of the answers were correct (and it wasn't rounding errors or something silly) I calculated the correct answer, showed all my computations (which included dimensional analysis and a vector diagram showing forces) and then tried to explain it to the people when they scored the test.
The answer that they said was correct did not accounted for the depth of the water and they made me sign a sheet saying I understood all the questions/answers that I got wrong on the test. They were none too happy when I told them their test was wrong.
The answer that they said was correct did not accounted for the depth of the water and they made me sign a sheet saying I understood all the questions/answers that I got wrong on the test. They were none too happy when I told them their test was wrong.
CenTexDivin
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h90:yeah in 12.000 meter deep and minus 5 degree you get complete different figures
I had somewhere a table on how water get compressed under pressure, but can't find it anymore. Didn't use it for at least 10 years
Don't forget to convert to the Kelvin scale.
serambin
Guest
Of course using the empirical technique, one could just attach lift bags and inflate them until the buoyancy becomes positive and it floats. Assuming you have enough bags and air.
dumpsterDiver:
How did you do with those type questions on the DM physics exam or on the pre-test in your IDC? They don't account for depth anyplace.
Water isn't very compressible so the density is fairly constant with depth and the questions are usually worded so as to ask how much water needs to be displaced in order to get neutral or to a specific positive buoyancy so how far off was their answer?
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