A weightless rope is thrown over a log. A body of mass $m$ is tied to one end of the rope. Some force $F$ is applied vertically downward to the other end. Because of the friction between the rope and the log, the minimum value of the force that lifts the body up is $\alpha mg$, where $\alpha$ is a coefficient greater than one and independent of $m$. Find the minimum value of force $F$ sufficient to hold body $m$ stationary.
Decision:
The problem is completely similar to problem 17. The minimum value of force $F$ at which body $m$ is stationary is $F_{min} = \frac{mg}{ \alpha}$.
Decision:
The problem is completely similar to problem 17. The minimum value of force $F$ at which body $m$ is stationary is $F_{min} = \frac{mg}{ \alpha}$.