A copper bar is $800mm$ long. An aluminum bar is $0\mathrm{.}10mm$ shorter than the copper bar. Both bars start at room temperature and are heated at a rate of $4\mathrm{.}0C$ per minute. How long will it take until both bars are the same length? The coefficient of thermal expansion is $16\mathrm{.}6{10}^{-6}\frac{1}{C}$ for copper and $23\mathrm{.}6{10}^{-6}\frac{1}{C}$ for aluminum.

Answer in seconds.