Answer
The vertical compression of the beam is $9.67\times 10^{-5}~m$
Work Step by Step
$Y = \frac{F/A}{\Delta L/L_0}$
$Y$ is Young's modulus
$F$ is the force
$A$ is the cross-sectional area
$\Delta L$ is the change in length
$L_0$ is the original length
We can find the vertical compression:
$\Delta L = \frac{F~L_0}{Y~A}$
$\Delta L = \frac{(5.8\times 10^4~N)(2.5~m)}{(200\times 10^9~N/m^2)(7.5\times 10^{-3}~m^2)}$
$\Delta L = 9.67\times 10^{-5}~m$
The vertical compression of the beam is $9.67\times 10^{-5}~m$.
