13
votes
Pound-force (lbf) vs Pound-mass (lbm)
$Lb_m$ is not the base unit. The Slug is the base unit.
$32.2\ lb_m = 1\ slug$
To convert $1\ lb_m$ to $lb_f$:
$1\ lb_m * \frac{1\ slug}{32.2\ lb_m} * 32.2 \frac{ft}{s^2} = 1\ lb_f$
Therefore $1\ ...
- 155
7
votes
Pound-force (lbf) vs Pound-mass (lbm)
The textbook is incomplete. Newton's Law is usually written $F=ma$. The SI unit of mass is the $kg$ and that of force is the $N$. One of the advantages of SI is that it clarifies the distinction ...
- 304
5
votes
Accepted
Pound-force (lbf) vs Pound-mass (lbm)
I wrote this paper in response to a declaration made by Dynamics Professor that "there is no difference between a lbm and lbf." The discussions from the students that followed exposed a huge ...
4
votes
Pound-force (lbf) vs Pound-mass (lbm)
1 pound mass is that mass that weighs one pound in 1 g gravity. For most practical cases, a pound mass and a pound weight define the same amount of stuff on the surface of the earth.
To define a ...
- 11.3k
4
votes
Pound-force (lbf) vs Pound-mass (lbm)
There seems to be some confusion here. In the English (or American) system the "official" measure of mass is the slug. Turns out that 32.2 lbm = 1 slug. So to plug into the equation F=MA you can use M ...
- 71
4
votes
Pound-force (lbf) vs Pound-mass (lbm)
lbf has two definitions and a friend called Poundal
(1) EE System
The force required to accelerate 1 lbm 32.174049 ft/s^2 (i.e., acceleration due to gravity) However, the problem with this is that ...
3
votes
Accepted
Is there such thing as supreme board for international arbitrators?
They can't even write English on their certificate.
... training of good stand, and is in accord with American and
European standers...
That's an obvious typo. Of course it should say
... ...
- 12.4k
3
votes
ISO standards for drawing reserve equiptment in P&IDs
A P&ID should reflect reality
A P&ID that doens't reflect the actual piping construction is a flowchart, not a P&ID. P&ID's are used to determine valve lockout and blind flange ...
- 5,980
2
votes
Accepted
ISO standards for drawing reserve equiptment in P&IDs
From ISO 10628-1 Diagrams for the chemical and petrochemical industry —
Part 1: Specification of diagrams
4.4 Piping and instrumentation diagrams (P&ID)
All equipment, valves, and fittings shall ...
- 2,477
2
votes
Accepted
US customary units below 1 mil/thou?
50μm → 0.002" or 2 thou or 2 mils?
I've seen both 0.002" and 2 mils. On a drawing it would always be 0.002". In a specification document it could be either. I've never seen 2 thou written in a ...
- 2,626
1
vote
Accepted
Where to find a complete overview for ISO P&ID standards?
Well basically the text of the standard is available at:
iso.org
Though ISO has a number of local distributors, that may be more convenient to deal with or even get free acces through university ...
- 3,522
1
vote
Pound-force (lbf) vs Pound-mass (lbm)
lbm and lbf are not the same -- they are only of the same value in one situation, when dealing with gravity at sea level... examine a situation without gravity, the force produced by a jet of water.
...
- 11
1
vote
Pound-force (lbf) vs Pound-mass (lbm)
I will try to make it as simple as possible and will provide an example:
-First of all ignore the word slug... I know it is the standard unit for mass and so is lbm. you will see lbm used in your ...
- 11
1
vote
Pound-force (lbf) vs Pound-mass (lbm)
Absolutely, yes you can. In fact, the mass of a slug is derived from the acceleration due to gravity.
- 3,135
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