Question

Suppose that you are standing on a train accelerating at 0.40g. What minimum coefficient of static friction must exist between your feet and the floor if you are not to slide?

Answer 1

Limiting friction must be acting in this case and must be sufficient enough to give me the same acceleration as that of the train's. So, equate the acceleration produced due to lim friction, with that of the train. Convey doubts if any.

Answer 2

\[\mu mg=ma\]

\[\mu g = a\]

\[\mu=a/g\]

Answer 3

hope this helps