The cord of a musical instrument is fixed at both ends and has a length \(2 \mathrm{~m}\), diameter \(0.5 \mathrm{~mm}\), and density \(7800 \mathrm{~kg} / \mathrm{m}^{3}\). Find the tension required in order to have a fundamental frequency of (a) \(1 \mathrm{~Hz}\) and (b) \(5 \mathrm{~Hz}\).