a$)$ For the truss shown, draw the

influence line for the axial force in bar JC

and JD and then compute the maximum

axial force $(T$ and C $)$ due to a moving load

$P=15kN.$

b$)$ For the truss shown below, identify the bars with zero axial forces. Show your answer with a sketch

of the truss and zero force bars marked with an $"0"$

SHOW SOLUTIONS.