A student working in a laboratory has to remove a heavy box with new equipment from its initial position on the floor to the opposite wall of the room, which is d metres away. She may choose: either to pick up the box, to carry it in her hands across the room, and then to drop it on the floor in the new place; or to attach a rope to one of the corners of the box and pull the box along the floor to the new place. The mass M of the box and its contents is printed on the package. The coefficients of static and kinetic friction μs and μk for the box material and the floor are available. After performing some calculations, the student notes that μk<μs<1 and chooses the second method.
1) What physical quantities should the student compare to choose the proper method of moving the heavy box?