Static Equilibrium Cable Problem

[Seraph404]

Homework Statement

In fig. 13-32, a 50.0 kg uniform square sign, 2.00 m on a side, is hung from a 3.00 m horizantal rod of negligible mass. A cable is attached to the end of the rod and to a point on the wall 4.00 m above the point where the rod is hinged to the wall. (a) What is the tension in the cable? What are the magnitudes and directions of the (b) horizantal and (c) vertical components of the force on the rod from the wall?

Homework Equations

Net force = zero
Net torque = zero

The Attempt at a Solution

I don't understand how there is a vertical component exerted by the wall onto the rod.

 

[PhanthomJay]

If the weight of the sign was all concentrated at the right corner, there would be no vert comp of the wall on the rod; however, the sign's resultant weight acts thru its c.g., not at the corner. Try summing torques about the top left corner.

 

[Seraph404]

All right. Thanks so much!