The Free Body Diagram ■■ Consider the following case What are the forces acting on the plank? Isolate the plank from the rest of the world WP PF P/E Physics 121: Lecture 8, Pg 9Physics 121: Lecture 8, Pg 9 The Free Body Diagram... Consider the following case What are the forces acting on the plank ? Isolate the plank from the rest of the world. FW,P FP,W FP,F FP,E FF,P FE,P