Physics Help?

Question

A uniform rod of length 6 meters and weight 75 Newtons is supported on its right side by a cable. It left end rests against a wall, where friction is holding it in place. A 90 Newton sign is hung a distance of 4 meter from the wall.

1) What is the tension in the cable?
2) If the rod is not to slip at the left end, what is the minimum coefficient of static friction between the wall and the rod?

I know that there are no torques at the left end but I do not understand why that is. Also, I drew the diagram and got the x and y components but I am not sure what to do with the sin and cos.

Answer 1

Draw the free body diagram:

1)

Taking moment about A:

∑MA  = 0:

T(6) - (90)(4) - (75)(3) = 0

6T =585

T = 97.5 N