Why can’t a bullet proof vest protect you from a knife stab?

Question

I mean, it’s designed to stop a bullet which delivers much more force than a human being can ever produce during stabbing

In: 784

Answer 1

Two things

>delivers much more force than a human being can ever produce during stabbing

Nope if this were true newton’s 3rd law says I could not hold on to the gun when it fires.
A 9mm generates 500 ish newton of force. while a average adult man can punch with about twice that. pro boxers can hit with 5000 newtons of force.

Second getting a knife through a IIIA vest, Assuming it’s not cut resistant, is NOT trivial. You need a sharp strong knife and a lot of upper body strength.
If it is cut resistant you don’t stand a chance in hell.
In this video the guy is standing over the vest and stabling down into it. So every advantage possible given to the knife. It barely pokes through.