Problem $2(5$ points$)$

Using the Method of Virtual Work, find the vertical displacement at Point A on the truss to the right. Assume that $E=200$GPa and that cross$-$sectional area $A=300m{m}^2.$

$C=$ Pin

$D=$ Pin

$($Despite the two pins, this is determinate $-$ you can solve this. We know that the vertical reaction force at $D$ must be zero by taking the method of joints at location D$.)$

Warning $-$ Units for E and I are very important! Be careful and make sure they match with the units for the loads and lengths given in the problem.

$1$GPa$={10}^9\frac{N}{m^2}=1k\frac{N}{m}{m}^2$I find this problem is easier if you convert everything to millimeters and kilo$-$Newtons, but Newtons and meters is fine too.