1. The problem statement, all variables and given/known data The coefficient of friction between the trains wheel's and the rail on a frosty day is 0.1, What is the steepest slope (expressed in the form ''1 in n'') that the train can climb without slipping. 2. Relevant equations Ff = μ(Fn) 3. The attempt at a solution I have no idea. Don't want a solution, just a little guidance would be much appreciated. I understand that the point where the train will begin to slip is when the maximum friction force is reached but I can't see how to apply this to this question.