Basic Statics problem, forces on a Truss

[coffeebird]

Homework Statement

The truss is supported by a pin at A and roller at B. Determine the support reactions.

Homework Equations

sum of forces along y-axis, sum of forces along x-axis, sum of all torques

The Attempt at a Solution

Sum of x= Fax+ Fbx+ 5sin45=0
Sum of y=Fay+Fby-10 -5sin45=0

I would like to know how the forces act on the truss, and why. It hasn't been very well explained to me. Thank you : )

 

[pongo38]

In a real structure there would be a lot more forces representing self-weight, snow, wind, loads from internal cranes etc. In this case, which is a 'learning example' you could imagine the 10 kN load as representing the self weight and other permanent loads, and the 5 kN load as a simplified wind load, which, in reality would be a variable distributed load.