Charge calculations {Ans: Six step problem solving format}External Charge {Ans: Charges that are placed on the surface of the target without considering placement techniques , use a flat, square charge with a thickness to weight ratio of 1:3 P=D^2/40 or P=0.025D^2}8 inches {Ans: 300 or more pounds}Abatis {Ans: Fallen tree obstacles are made by cutting trees that remain attached to their stumps TNT required for a test shot P=D^2/50 or P=0.02D^2}Timber Cutting charges {Ans: plastic explosives}Priming {Ans: The direction in which the shock wave travels through the explosive charge}