Disclaimer: Don't Try This At Home Or Anyplace Else For That Matter.
First off, Shop Class is where you learn about such things as 1) Wood Working; 2) Sheet Metal Work; 3) Drafting; and 4) Smithing with a forge. In my school there was one classroom that taught all 4 subjects. Interestingly the table saw was remarkably close to the forge. Beneath the table saw there was, as matter of course, an abundance of sawdust. Now the forge was a commercial size forge with no speed limit so to speak. If you were allocated to work with forge and anvil you could load up the forge with coal and crank in the air to your heart's content. Now then, with the forge at full heat, all one had to do was take a few steps in the direction of the table saw; pick up a handful of sawdust; and pitch the sawdust at the front of the forge. In this scenario the sawdust never reaches the forge and explodes in a red fire ball; but it all happens incredibly fast so unless the teacher is actually looking at the forge, they see nothing. Yes there is a distinct KABOOM but fortunately the speed of sound is slower than the speed of light and not the other way around. So the teacher hears the KABOOM but then turns to look and sees nothing but students hard at work. ;-)