Aside In this example the plank is not moving And it is not accelerating! So FNET ma becomes FNET =0 PW For+ FDE=O PWP F P E F PE This is the basic idea behind statics Physics 121: Lecture 8, Pg 11Physics 121: Lecture 8, Pg 11 Aside... In this example the plank is not moving... And it is not accelerating! So FNET = ma becomes FNET = 0 This is the basic idea behind statics. FP,W + FP,F + FP,E = 0 FP,W FP,F FP,E