The Physics of the N95 Face Mask

IT'S 2022, AND by now we've all been wearing masks for nearly two years. AND unless you are a surgeon or a construction worker who Was already wearing them daily, in those two years you've probably learned a lot about them -- which ones you like best, where to get them, and whether you have any extras stashed in a coat pocket or somewhere in your car.

But do you know what makes the prized N95 maskso special? Let's find out.

Electric Charges & health food

Finally, The masks in regular Cloth or paper face filter out Particles by affix blocking them -- but The fibers in an NIOSH N95 mask also use a great physics trick. These fibers are electrically charged.

Electric charge is one of the fundamental properties of all particles. Just about everything around you is made of three particles: the proton, the electron and the neutron. (For now, Let's ignore muons and neutrinos -- Both Fundamental Particles that Actually Exist -- As well as other Particles that are theoretically possible.)

Just as every particle has a mass, The proton has a positive electric charge with a value of 1.6 x 10-19 coulombs, the unit for measuring electric charge. The electron has the exact opposite charge. That leaves the neutron with zero Charge (thus the "neut" part of "neutron").

The electric charge is a key part of the electrostatic interaction, the force between electric charges. The magnitude of this force depends on the magnitudes of the two charges and the distance between them. We can calculate this force with Coulomb's law. It looks like this:

In this expression, K is a constant with a value of 9 x 109 N×m2/C2. The charges are Q1 and Q2 and The distance between them is R. This will give a force in newtons. If the two charges are both the same sign (either both positive or both negative) then this will be a repulsive force. If the two charges are different signs, then the force is attractive.