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Pounds are a unit of weight, not of mass. 10 lbs of feathers is whatever amount of feathers causes a scale to display 10 lbs. If the scale also displays 10 lbs
by chongli 2y ago
Pounds are a unit of weight, not of mass. 10 lbs of feathers is whatever amount of feathers causes a scale to display 10 lbs. If the scale also displays 10 lbs for the quantity of bricks, then they weigh the same, regardless of any differences in mass.
- wongarsu 2y agoIs this still true? I thought pounds are now defined in terms of kilograms (about 0.453)? Because kilograms are definitely a unit of mass, not weight. Or is the pound defined as some amount of kilograms at a specific point on earth, in a specific phase of the moon?
- chongli 2y agoIt seems the pound has since been redefined and split into separate units: pound mass and pound force, the former in terms of kilograms (1 lb = 0.45359237 kg) and the latter in terms of the force exerted by one pound of mass in earth’s gravitational field (standard g = 9.80665m/s^2). So using the word pound without qualification is ambiguous in contexts where it’s not clear whether mass or force is meant.