Two cylindrical wires of equal radius 0.60 mm are soldered end-to-end to form a single conductor. The first segment is 0.80 m of constantan (resistivity 4.9×10−7Ω⋅m). The second segment is copper (resistivity 1.7×10−8Ω⋅m) of unknown length L. When a potential difference of 5.0 V is applied across the entire series conductor, the current is measured to be 2.0 A. Calculate the length L of the copper segment.