Question $1$

$(10-20$min$)$

A steel beam is placed vertically in the basement of a building to keep the floor from sagging. The

load of the beam is $5\mathrm{.}8{10}^{4}N,$ the length of the beam is $2\mathrm{.}5m$ and the cross$-$sectional area of the

beam is $7\mathrm{.}5{10}^{-4}{m}^2.$ The Young's modulus of the steel beam is $200$GPa.

$($b$)$ Calculate the compressive strain.