[ 3 / biz / cgl / ck / diy / fa / g / ic / jp / lit / sci / tg / vr / vt ] [ index / top / reports / report a bug ] [ 4plebs / archived.moe / rbt ]

/vt/ is now archived.Become a Patron!

/sci/ - Science & Math

View post   

[ Toggle deleted replies ]
File: 5 KB, 416x240, pressure.jpg [View same] [iqdb] [saucenao] [google] [report]
12659209 No.12659209 [Reply] [Original] [archived.moe]

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

>> No.12659251

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

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] [report]

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

>> No.12659342

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] [report]

Human Physiology by Sherwood (see pic related)

>> No.12659545

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


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

>> No.12659658

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] [report]


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

>> No.12660647

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

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] [report]

F/A isnt that just m

>> No.12663439
File: 28 KB, 499x481, 1598906442413.jpg [View same] [iqdb] [saucenao] [google] [report]


Name (leave empty)
Comment (leave empty)
Password [?]Password used for file deletion.