Correct Answer $($Used$)$

A pin$-$connected structure consists of a rigid beam ABCD and two supporting bars. Bar $(1)$ is an aluminum

alloy $]$ with a cross$-$sectional area of $A_1=2,400m{m}^2.$ Bar $(2)$ is a bronze alloy $[E=100$GPa $]$ with a

cross$-$sectional area of $A_2=6,000m{m}^2.$ All bars are unstressed before the load $P$ is applied; however, there is

a $3-$mm clearance in the pin connection at $A.$ If a load of $P=695kN$ is applied at $B,$ determine the normal force

in bar $(1).$ THE ANSWER MUST BE $345$ KN