This video explains how virus particles 20 um in size can go when someone coughs.
This video explains how far small particles can go when a human coughs. And this explains why we should wear a mask AND keep a distance of at min 6 feet. (9ft is better and we need to keep a distance from an infected person)
[url]https://www.cnn.com/2020/11/06/health/cough-droplets-coronavirus-study-wellness/index.html[/url]
