(Solved): A rigid rod of length 2m and weight 20N is placed between wall and floor making an angle wit ...

A rigid rod of length $2\mathrm{m}$ and weight $20\mathrm{N}$ is placed between wall and floor making an angle $\alpha$ with the floor as shown in the following figure. The contact between rigid rod and wall is smooth at A while with the floor is rough at $B$. The coefficient of static friction between rod and floor is ${\mu }_{\mathrm{s}}=0.55$. a) If the angle $\alpha =60^{\circ }$, the friction at $B$ is $N$ and the static friction at $B$ is N, thus the system is