Claude 2.1: A kilogram of feathers would weigh the same as a kilogram of feathers.

This is a trick question based on the fact that a kilogram (kg) is a unit of weight or mass. One kilogram would always equal another kilogram. It would not matter whether we are talking about a kilogram of feathers, a kilogram of steel, or a kilogram of anything. Since they are the same unit of measure, a kilogram of feathers and a kilogram of feathers weigh exactly the same.