Rigid bar ABC is supported by member $(1),$ which

has a cross$-$sectional area of $0\mathrm{.}6$ in$.{?}^2,$ an elastic

modulus of $E=9800$ksi, and a coefficient of

thermal expansion of $a=12\mathrm{.}8\frac{{10}^{-6}}{}F.$ Assume

that $a=85in..,b=40$ in$.,$ and $c=130in.$ After load

$P$ is applied to the rigid bar and the temperature

rises $55F,$ a strain gage affixed to member $(1)$

measures a strain increase of $2178.$ Determine

the magnitude of applied load $P.$

Note: Assume the strain measuring system does

not automatically compensate for temperature

changes.

Answer: