Why does a plastic bag make a loud sound when you move it and a cotton bag is almost silent?

Question

Why does a plastic bag make a loud sound when you move it and a cotton bag is almost silent?

In: Physics

Answer 1

Air freely moves through cotton bags, plastic bags are air tight. Since the plastic bag is air tight air that would pass through the bag doesn’t and instead bounces off – this is what sound is, air bouncing around.