Given a copper wire of length \(100 \mathrm{~cm}\), radius \(0.8 \mathrm{~mm}\), and resistivity \(1.68 \times 10^{-8} \Omega \cdot \mathrm{m}\), find its resistance and current through the wire if connected to a \(20.0-\mathrm{V}\) battery. If the wire is stretched uniformly to 4 times its original length, what will be its new resistance?