Math Mechanics

[Guest]

A uniform rod AB of length lm and mass m kg rests with one end touching a rough vertical wall at B the rod is kept horizontal by a light inextensible string AC where C lies on the wall directly above B The plane ABC is perpendicular to the wall and angle BAC is a, where tan a - 5/12.
a) Show that the tension in the string is 13/10mg N.
b) Calculate the coefficient of friction between the rod and the wall