Consider the truss shown in $($Figure $1).$ For each member

$A=650m{m}^2,E=200$GPa.

$={\displaystyle \underset{?}{\overset{?}{}}}N(\frac{\text{d}\text{e}\text{l}\text{N}}{\text{d}\text{e}\text{l}\text{P}})\frac{AE}{L}$

$={\displaystyle \underset{?}{\overset{?}{}}}\frac{\text{N}\text{A}\text{E}}{nL}$

$={\displaystyle \underset{?}{\overset{?}{}}}N(\frac{\text{d}\text{e}\text{l}\text{N}}{\text{d}\text{e}\text{l}\text{P}})\frac{L}{AE}$

$={\displaystyle \underset{?}{\overset{?}{}}}\frac{nNL}{AE}$

Correct

Part B

Determine the vertical displacement of joint $E$ measured downward. Use Castigliano's theorem.

Figure

Express your answer to three significant figures and include the appropriate units. Enter positive value if the displacement is downward

and negative value if the displacement is upward.

${}_{B_v}=$