Explanation:
Δ[tex]L_{BC}[/tex] = Δ[tex]L_{AB}[/tex]
[tex]\frac{(Q - 4000)(0.5)}{3.14* 0.03 *0.03 *70*10^{9} }[/tex] (1)
= [tex]\frac{4000*0.4}{3.14*0.01*0.01*70*10^{9} }[/tex]
Q = 32,800 N
now put this value in equation 1.
Deflection of B = [tex]\frac{(32800-4000)(0.5)}{3.14*0.03*0.03*70*10^{9} }[/tex]
= 0.0728 mm