Solve Shear Force & Moment Equation Homework

[tj1989]

Homework Statement

The problem and the solution are in attached.

Homework Equations

The Attempt at a Solution

What I'm confused about is the moment equation. Why does the equation reference both Ay and Ax, but it only considers the 3 kip force in one direction. Why doesn't it have an x-component, and a y-component?

 

[PhanthomJay]

Homework Statement

The problem and the solution are in attached.

Homework Equations

The Attempt at a Solution

What I'm confused about is the moment equation. Why does the equation reference both Ay and Ax, but it only considers the 3 kip force in one direction. Why doesn't it have an x-component, and a y-component?

It does, Fx = 3 sin30 and Fy = 3 cos 30. When summing moments about B, however, it is easier to use the resultant force F in calculating the moment, rather than use the sum of its component moments to calculate the moment.