|MLA Citation:||Bloomfield, Louis A. "Question 628"|
How Everything Works 21 Jan 2018. 21 Jan 2018 <http://howeverythingworks.org/print1.php?QNum=628>.
Bulletproof glass is actually a multi-layered sandwich of glass and plastic—it's like the front windshield of a car, but with many more layers. When a bullet hits the surface of the sandwich, it begins to tear into the layers. But the bullet loses momentum before it manages to burrow all the way through to the final layers. The bullet's energy and momentum are transferred harmlessly to the layers of glass and plastic.