Final answer:
A pound of iron and a pound of feathers weigh the same. The difference lies in their density: a pound of feathers will occupy a larger volume than a pound of iron due to feathers having a lower density.
Step-by-step explanation:
A student has asked the question: What weighs more? A pound of iron or a pound of feathers? This question is an excellent demonstration of the distinction between mass and density. When we compare a pound of feathers to a pound of iron, we are essentially comparing two objects with the same weight, as a pound is a standard unit of weight.
In terms of density, iron is much denser than feathers. This means that for the same weight, the volume of feathers will be much greater than the volume of iron. If we had a ton of feathers and a ton of iron, they would weigh the same, but the feathers would take up a much larger space due to their lower density, as seen in Figure 11.3 and Figure 11.4 from the provided references.
To summarize, a pound of iron and a pound of feathers weigh the same because they both represent a pound. However, the feathers occupy a larger volume because of their much lower density compared to iron. This concept also applies to other comparisons like a ton of bricks versus a ton of feathers.