The rigid beam $BC$ is supported by rods $(1)$ and $(2).$ The cross$-$sectional area of rod $(1)$ is $8m{m}^2.$ The cross$-$sectional area of rod $(2)$ is $16m{m}^2.$ For a uniformly distributed load of $w=2\mathrm{.}1k\frac{N}{m},$ determine the length a so that the normal stress is the same in each rod. Assume $L=3\mathrm{.}55m.$

Answer: $a=$