(I) Suppose you are standing on a train accelerating at 0.20 g. What minimum coefficient of static friction must exist between your feet and the floor if you are not to slide?
Solution 38P: We have to find the minimum value of coefficient of static friction, to prevent the body from sliding as the train accelerates. Step 1 of 3 Concept: Newton’s second law: The net force F acting on an object of mass m produces an acceleration a in that object. Mathematically, F= ma. Frictional force also acts on the surface of the bodies in contact whenever their is relative motion between between the two bodies. Free body diagram of a body gives the diagrammatical representation of all the forces acting on the body in terms of magnitude and diagram, under the given situation. Step 2 of 3 Figure below shows the free body diagram of the person standing on an accelerating train. a Acceleration of the train = 0.20g F NNormal reaction on the person in upward direction mg Weight of the person acting vertically downward direction F frrictional force acting at the contact surfaces Coefficient of static friction