I have a question for homework, and this is a high school physics class. The question reads: Suppose that you are standing on a train accelerating at 2.0m/s^2. What minimum coefficient of static friction must exist between your feet and the floor if you are not to slide? I've drawn a free body diagram, and motion in the Y dimension doesnt really matter. In the X dimension, I THINK there are 2 forces: Force of the train, and Force of friction. What I've come up with is this: Fnetx=0 (Since I'm not accelerating in relation to the train itself. I'm hoping this assumption is right, or everything else is wrong.) Fnetx=Ft-Ff Ft=Ff Ff=9.8mu, and Ft=2m (This is where I'm getting sketchy. Is the force of the train on the person the same as acceleration x the persons mass?) 9.8m/2m=u u=.2 I'm basically posting to verify my answer, since I'm not entirely sure if the route I took to get to it was right. Thanks for reading!