- #1

TheNormalForc

- 12

- 0

**A sign with weight 800 N is hung from point B at the end of a uniform hoizontal rod of weight 300 N as diagrammed below. The rod is attached to the vertical wall by a hinge at point A. The supporting cable is attached to the rod at B and to the wall at C. The cable makes a 42 degree angle with the rod.**

A.Find the magnitude of the total force R exerted on the hinge at point A. note that the total force has both horizontal and vertical components.

B.The Cable has a tensile strength of 3216N. Find the minimum possible angle that the cable can make with the rod if it is to support the rod and sign without breaking.

A.Find the magnitude of the total force R exerted on the hinge at point A. note that the total force has both horizontal and vertical components.

B.The Cable has a tensile strength of 3216N. Find the minimum possible angle that the cable can make with the rod if it is to support the rod and sign without breaking.

**Torque=Fsin(theta)r**

I know exactly how to do A. I describe the torque equation, equal to zero and solve for P, and then use that to find Rx and Ry, and then R itself. But to create a valid equation I need to know the length of the bar, don't I? It's really confounded me.

B has stumped me completely.