Question

A pound of feathers or a pound of rocks?Which is heavier? 

Answer 1

it's 1 pound So mass would be the same of 1 pound of feathers and rocks

but if it's weight and not in vacuum

then as buoyant force on feather would be more because it's volume ×pg As volume occupied by 1 pound would be more
so due to more buoyant force it has less weight