Engineering Statics

D-18


Determine the force in members FG and FH of the truss shown.

A FBD of the truss is drawn in order to solve for external forces.


B<sub>x</sub> is zero because no other external forces exist in the 
x-direction.
The truss has been cut vertically through members EG, FG and FH. 
FBD's of both sides have been drawn.
From the right FBD, FG is the only member with a vertical component, hence 
it is the only unknown in the y equilibrium equation.
A moment about G allows us to solve for the other unknown, FH.