Answer in short
1) what is gslvanisation?
who knows the answer they are good in studies

Galvanisation or galvanization (or galvanizing as it is most commonly called) is the process of applying a protective zinc coating to iron or steel, to prevent rusting. The most common method is hot dip galvanizing, in which steel sections are submerged in a bath of molten zinc.

you would expect a sound wave to speed up. - b)

it is because acrylic blanket have acrylic textile fiber

explanation:

its is better than wool blanket