Answer to Question #122 in Mechanics | Relativity for Anthony
There is a box of chocolates and an apple on the table in the train. Why did the apple roll back (with regard to the train) and the box of chocolates remained in place when the train began its motion?
Different friction forces influence the apple and the box of chocolates: the box is under a considerable friction force, and the apple is under a much weaker force of rolling friction. In the case of the box, friction force compensates the inertia, and in the case of apples, friction force can not compensate the inertia.