A system of three blocks of different masses is placed on a horizontal floor. Blocks 2M and M are connected by a light string that passes over a frictionless pulley mounted on block 3M. Block 2M is initially held in place. Find the minimum value of the coefficient of static friction between block 3M and the floor that allows block 3M to remain at rest after block M is released. The coefficients of friction between the block of mass 3M and that of mass 2M are given.

Guidelines for contributors

  • We ask that all solutions, preferably in Word format, be submitted to the dedicated email address challenges@aapt.org. Each message will receive an automatic acknowledgment.

  • If your name is—for instance—Dolores Gende, please name the file “Gende17Nov” (do not include your first initial) when submitting the November 2017 solution.

  • The subject...

Supplementary Material

AAPT members receive access to The Physics Teacher and the American Journal of Physics as a member benefit. To learn more about this member benefit and becoming an AAPT member, visit the Joining AAPT page.