Question

The following two statements are made with reference to the planar truss shown below:

I. The truss is statically deternminate
II. The truss is kinematically determinate

With reference to the above statements, which of the following applies?

• A. II is true but I false
• B. I is true but II is false
• C. Both statements are false
• D. Both statements are true

Answer 1

The correct option is B I is true but II is false


$D_s=m+r-2J$
$m\to$ no. of members = 12
$r\to$ no. of reactions at support = 6
$J\to$ no. of joints = 9
$D_s=12+6-2\times 9=0$.
$\therefore$ The truss is statically determinate.
The truss is kinematically indeterminate because there are 6 joints where unknown joint displacements are possible.