Q$1.$ For the truss shown below and using virtual work method:

a$.$ Determine the horizontal displacement of Node $D$ if an $8-$kN point load is horizontal ly

applied on the same point $($Node D$)$ toward the left side of the truss.

$(50\%)$

b$.$ Determine the horizontal displacement of Node $D$ if the temperature of members $AD$ and

$DC$ increases by $50C.$ Ignore the applied load of Part $($a$)$ in this question.

$(20\%)$

c$.$ Determine the horizontal displacement of Node D if member AC is fabricated $20mm$

shorter than the intended length by mistake. Ignore the applied load of Part $($a$)$ in this

question.

$(20\%)$

Assume that the area of each member is $200m{m}^2(A=200m{m}^2),$ the modulus of elasticity for

all members is $200$GPa$(E=200$GPa$),$ and the coefficient of thermal expansion $()$ is $12{10}^{-6}$

$(\frac{1}{}C)$ for the members.