Answer to Question #275900 in Physics for may

Question

What is the relationship between the Block + Mass and Weight hanger + Mass with regards to coefficient of friction?

Answer 1

For Block of mass M + Mass m hanging over a pulley:

$$a=g\frac{m-\mu M}{m+M}.$$

For a weight hanger with mass over a frictionless pulley, there is no such relation because the friction is ignored.