Solving for friction with only acceleration

AI Thread Summary
To determine the minimum coefficient of static friction required to prevent slipping on a train accelerating at 0.2g, the relationship between force, mass, and friction must be considered. The normal force can be defined as the weight of the person, which is dependent on their mass. By using the equation F = ma and recognizing that the force of friction must equal the mass times the acceleration, one can express the static friction force as μ times the normal force. The solution can be simplified by letting mass be a variable, allowing the equation to be solved without needing its actual value. Understanding these relationships is crucial for solving the problem effectively.
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Homework Statement



You are on a train accelerating at .2g; what is the minimum coefficient of static friction that your shoes have to have with the base of the train in order to not move?

You are only given the acceleration of the train. Not your mass or the natural force.


Homework Equations



F=MA, F= mew * natural force


The Attempt at a Solution



I have tried approaching it from several diffrent angles, looking it as F=MA and F= mew * natural force, but with only the acceleration, I do not see a way to solve the problem. Their are just too many variables. If I knew the mass of the person, I could easily solve it, by dividing the force by the natural force, but you aren't givin that.
 
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What you call 'natural force' should be the normal force. You don't need the actual mass--just call it 'm' and see what happens. How do you calculate the normal force in this situation?
 

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