Engineering Statics


For the boom and loading shown, determine the tension in cord BD and the reaction at point C.

The FBD shows the 3 kip force at A, the tension and the two components of force at C.  Note that  for a cord the 
force must be along the cord.  The x and y components hence 
are proportional to the geometry.
The geometry for the cord is a 24,32,40 (3,4,5) triangle.
The moment equation is written about point B.
Force equilibrium exists in the x-direction.
Force equilibrium exists in the y-direction.
The equations are rewritten with all C<sub>x</sub> terms 
under each other, C<sub>y</sub> terms under each other and 
T terms under each other on the left side of the equation. 
Constants are on the right side of the equation. 
The simultaneous equation solver on your calculator can solve 
for three equations in 3 unknowns.
Solutions for the three unknowns C<sub>x</sub>, C<sub>y</sub> and T 
are from the calculator.