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/sci/ - Science & Math


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12659209 No.12659209 [Reply] [Original]

Are the units: kg/m^2
acceptable for depicting pressure? I recognize they aren't common, but surely they're fine?

>> No.12659251

>>12659209
Not the right dimension, a pressure is a force over a surface, not a mass over a surface. You're missing an acceleration.

>> No.12659252

>>12659209
mass over area?

>> No.12659294
File: 8 KB, 379x74, Screen Shot 2021-02-02 at 6.39.28 PM.png [View same] [iqdb] [saucenao] [google]
12659294

>>12659251
>>12659252
In the context of calculating hydrostatic pressure?:
metres * kg/m^3 = kg/m^2

>> No.12659342

>>12659294
still missing acceleration, i.e. P = rho g h for example. what is this textbook youre referencing

>> No.12659465
File: 687 KB, 573x698, Screen Shot 2021-02-02 at 7.04.09 PM.png [View same] [iqdb] [saucenao] [google]
12659465

>>12659342
Human Physiology by Sherwood (see pic related)

>> No.12659545

>>12659465
Maybe that's acceptable in the field of medicine...but in phys/chem they are not accepted.

>> No.12659621

It's acceptable in the context of medicine. I mean, it's a more visualizable unit for doctors and other retards. It assumes standard g acceleration which is the case 99.999999999999999+% of the time anyway. But I do wonder if it's a forced metric analogy of PSI for that
>>12659465 Canadian Edition. PSI is pounds per square inch. American units don't differentiate between mass and weight (force), they just assume Earth g.

>> No.12659645

>>12659209

Reasonably kg/m^2 is an acceptable measurement of pressure.

>> No.12659658

>>12659621
They do actually, usually lb_f and lb_m for pounds of force and pounds of mass. At standard g, lb_f = lb_m of course so in most cases it is just up to context of whether to differentiate

>> No.12660251
File: 161 KB, 1071x568, fixed glasses.jpg [View same] [iqdb] [saucenao] [google]
12660251

>>12659209
>>12659251
>>12659252

kek, OP is calculating the density of a two-dimensional piece of graphite

>> No.12660647

>>12659342
>>12659251
stop being dense. kgf/m^2 IS in fact a quantity of pressure.
nobody uses it because atmospheric pressure would be much less than 1 in these units, making them a shit choice. SI people use kilopascals, bar, millimeters of mercury, while americans use psi and inches of mercury, but all of which assign a reasonable value to 1 atm.

>> No.12660710

>>12659645
wrong because what if your kg is on the moon or jupiter?

>> No.12662840
File: 803 KB, 978x714, 1572634617379.png [View same] [iqdb] [saucenao] [google]
12662840

F/A isnt that just m

>> No.12663439
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12663439

>>12662840