Is Our Weight Measured in lbm or lbf?

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SUMMARY

The discussion clarifies that weight is measured in pound-force (lbf), while mass is measured in pound mass (lbm). When weighing oneself, domestic scales typically display mass in kilograms (kg) but are calibrated for Earth’s gravity, leading to potential discrepancies in different gravitational environments, such as the Moon. The relationship between weight and mass is defined by the equation involving gravitational acceleration, highlighting that weight varies with location. The conversation emphasizes the importance of context in understanding the term 'weight' in both scientific and everyday language.

PREREQUISITES
  • Understanding of weight vs. mass concepts
  • Familiarity with gravitational acceleration (e.g., 32 ft/s² on Earth)
  • Basic knowledge of unit conversions (e.g., lbm to kg)
  • Awareness of the implications of varying gravitational forces
NEXT STEPS
  • Research the differences between weight and mass in physics
  • Learn about gravitational acceleration on different celestial bodies
  • Explore unit conversion techniques between imperial and metric systems
  • Study the implications of weight measurement in various scientific contexts
USEFUL FOR

Students, educators, and professionals in physics, engineering, and any field requiring precise measurements of weight and mass, as well as individuals interested in understanding the nuances of measurement terminology.

txdw16
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I'm sure this has been asked before but it's annoying me. When we weigh ourselves is it in lbm or lbf?

Because we weigh different on say, the moon, our weight must be lbf right? But if I weigh 150 any unit converter will say I weigh 68kg. Or do I weigh 2.13kg? Can I say I weigh 21 Newtons?
\frac{150lbf}{32ft/s^2}*\frac{1lbm}{2.2kg}\cong2.13kg*9.8m/s^2\cong21N
 
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Domestic scales measure the force you apply to them so it would be reasonable for them to display the result in Newtons but they all assume they will be used on Earth and have scales calibrated in kg (or some imperial equivalent). In effect they attempt to display your mass. Since gravity isn't the same everywhere on Earth they won't display the correct mass everywhere.
 
This is an old chestnut. Essentially, Weight is the force which pulls you down and it can vary with position. One really has to come to terms with the common usage of the term 'Weight' and use the context of any statement to decide what is really meant. You can waste far too much time trying to reconcile the two worlds of Science and everyday life. There is a danger of getting a name for nerdiness if you inflict strict definitions on innocent people in civvy street.
 
Weight is measured in pound-force. Mass is measured in pounds, (or pound mass?). But the term "weigh" can mean many things in the English language, including general measurement. Example: "weigh a decision"
 
This certainly is a weighty subject.
 

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