>There are substantial engineering factors involved but how deep do you set a 40 foot long wood utility pole? There are quite a few answers to this one depending on who's doing it, location (latitude and soil), slope of location, grade of pole, wind loads, raptor protection ordinances, and other factors including the wood used. Oddly diameter of the pole has little effect if a relatively constant taper. But for this bit of trivia assume a single stand alone pole (not poles in a line), in central U.S., in dirt, and no crossbar, on level land.
Bonus for breaking the code for the following pole woods: WC,WP,JP,LP,NP,DF,SP,WL. One of these designators should appear somewhere on each pole.