BonezXBasement Dweller Premium Member join:2004-04-13 Canada 2 edits |
to 88615298
Re: Weights and measuressaid by 88615298:said by cowboyro:No they don't. A kilogram is a kilogram, whether on the Earth at the North Pole or on the bright side of the moon. Same for a meter, same for a liter. Actually the moon's gravity is 1/6 that of Earth so a kilogram on Earth would be 1/6 kilogram on the moon. i love when people apply Imperial theory to SI units, it just makes my day. an LB is a force(F=M*A), not a mass, weight is a measurement of force, a slug is a mass not a force a Newton is a force, not a mass, a kg is a mass not a force. gravity is calculated at 9.8m/s^2, or 32.15ft/s^2 Imperial units are arbitrary, where SI units are standardized. good example, a meter is how long it takes for light to travel in 1/299 792 458 of a second. |
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cowboyro
Premium Member
2012-Nov-14 10:25 pm
said by BonezX:i love when people apply Imperial theory to SI units, it just makes my day. an LB is a force Actually a lb is a unit for MASS not for force. 1lb is defined as 0.45359237 kilograms. said by BonezX:Imperial units are arbitrary, where SI units are standardized. They are not arbitrary at all. Not any more than SI units. There is a strong, well-defined relationship between imperial and SI units. |
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DataRiker
Premium Member
2012-Nov-14 10:42 pm
The term pound can refer to a mass or a force. The unqualified term "pound" is ambiguous.
If one wishes to be unambiguous you can refer to either a pound-mass or pound-force.
Or just use the SI units since they are designed to be unambiguous. |
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cowboyro
Premium Member
2012-Nov-14 10:58 pm
said by DataRiker:Since the term pound is unqualified it can refer to a mass or a force. The term pound denotes a mass (when we are talking about "weights"). The pound-force term denotes the gravitational force exerted by a 1lb mass on Earth. |
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DataRiker
Premium Member
2012-Nov-14 11:10 pm
Weight is a force, so if your going to use some subjective context for reference (which is unwise) lb force would be more fitting.
Since neither of you used "pound-force" [lbf] or "pound-mass" [lbm], any argument that one definition is more correct than the other is extremely silly.
The unqualified "pound" should never ever be used in anything but the most informal oral conversations.
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BonezXBasement Dweller Premium Member join:2004-04-13 Canada |
to cowboyro
said by cowboyro:said by DataRiker:Since the term pound is unqualified it can refer to a mass or a force. The term pound denotes a mass (when we are talking about "weights"). The pound-force term denotes the gravitational force exerted by a 1lb mass on Earth. LB is a measurement of force(weight is called the normal force of an object fyi), the imperial measurement of mass is the slug. |
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cowboyro
Premium Member
2012-Nov-15 9:27 am
said by BonezX:said by cowboyro:said by DataRiker:Since the term pound is unqualified it can refer to a mass or a force. The term pound denotes a mass (when we are talking about "weights"). The pound-force term denotes the gravitational force exerted by a 1lb mass on Earth. LB is a measurement of force(weight is called the normal force of an object fyi), the imperial measurement of mass is the slug. According to NIST it's officially defined as a unit of mass. What some people use it as has no bearing over the official definition. |
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BonezXBasement Dweller Premium Member join:2004-04-13 Canada |
BonezX
Premium Member
2012-Nov-15 9:34 am
said by cowboyro:According to NIST it's officially defined as a unit of mass. What some people use it as has no bearing over the official definition. » en.wikipedia.org/wiki/Sl ··· 8mass%29» en.wikipedia.org/wiki/No ··· al_forcemight want to also look outside the united states of stuck in the past, if you did calculations in the scientific community, or about ~90% of the countries in the world in lb you would be laughed at. |
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OldCableGuy to BonezX
Anon
2012-Nov-15 10:35 am
to BonezX
>good example, a meter is how long it takes for light to travel in 1/299 792 458 of a second.
Yeah, that doesn't sound arbitrary or anything. |
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3 edits |
to cowboyro
said by cowboyro:According to NIST it's officially defined as a unit of mass. What some people use it as has no bearing over the official definition. This is a rather silly point since force is defined using mass. When you understand your circular reasoning get back to me. |
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to BonezX
said by BonezX:said by cowboyro:According to NIST it's officially defined as a unit of mass. What some people use it as has no bearing over the official definition. » en.wikipedia.org/wiki/Sl ··· 8mass%29» en.wikipedia.org/wiki/No ··· al_forcemight want to also look outside the united states of stuck in the past, if you did calculations in the scientific community, or about ~90% of the countries in the world in lb you would be laughed at. The pound is the official unit for mass. Not force, mass. The slug is a derived unit that makes the 1:1 translation between units of time, length and force so that F=m*a |
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DataRiker
Premium Member
2012-Nov-15 10:27 am
Force is defined using mass.
If you use pound in science, you will be immediately asked to clarify if you mean force or mass. |
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DataRiker |
to OldCableGuy
it is arbitrary until you once again qualify "in a vacuum"
Science is very particular about details |
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