[填空题]
Suppose that you are standing owj86w kf)nn yav1tdm0zq4 41rn a train acceler-1*c7;euhbk, u ,uemn kz 8isxating at 0.20g. What minimum coefficinshu,mub,;e1izx k- 87e *kc uent of static friction must exist between your feet and the floor if you are not to slide?
