Engineering Statics

E-1


Three cables are used to tether a balloon as shown. Knowing that the balloon exerts a 700 lb. lifting force, determine the tension in each cable.

A FBD is drawn at point A.  In addition the length of 
all three cables are found.
The components of the tension in cable AB are proportional 
to the geometry.
The components of the tension in cable AC are proportional 
to the geometry.
The components of the tension in cable AD are proportional 
to the geometry.
Summing forces in the x direction: