They're the same amount.
It is rather a trick question. People are thrown off by the feathers (light things) and nails (heavier things) but pound are pounds. The pound of feathers will most likely be larger in volume than the pound of nails.
a pound of feathers
No....the AV pound is heavier. The Troy ounce is heavier than a AV ounce but there are only 12 troy ounces in a Troy pound compared to 16 in a AV pound. There is an old joke...What is heavier, a pound of Gold or a pound of feathers...? The pound of feathers... Because the troy pound of Gold is measured in Troy...which has a lighter pound.
They are both equally heavy, as they both weigh one pound. The weight of an object is determined by its mass, and in this case, both the pounds of feathers and the pounds of books have the same mass of one pound.
Both a Pound of Iron and a Pound of Air weight the same ... One Pound ... neither is 'heavier.'
Same. That's an old trick question but feathers were more commonly used than cotton.
One pound is is about 4.5 times heavier than 100 grams.
They are both exactly the same - they weigh a pound. However, the feathers will take up a lot more space (about 0.77942 litres for every kg of feathers - or 779 cm3/kg) whereas the lead would be much smaller (about 0.12700 itres for every kg of iron - or 127 cm3/kg).
A pound of bricks and a pound of feathers weigh the same because they both weigh one pound. The difference lies in their volume, with bricks being denser and taking up less space compared to feathers.
The question as I heard it years ago was phrased, "Which is heavier a pound of gold or a pound of feathers?" Gold, being a precious metal, is weighed on the Troy system, which uses a wimpy pound and a wimpy ounce. Feathers are measured on the avoirdupois system, which has 16 full ounces in a pound. Ah, but you asked about the kg! As far as I know, a kg is a kg. So ten thousand grams of copper are heavier than one thousand grams of gold. (Technically, a kg is mass rather than weight, but that is another problem.)
They weigh the same.
They both weigh the same -- one pound.