A \(10-\mathrm{kg}\) block is attached to a spring of stiffness \(3 \times 10^{4} \mathrm{~N} / \mathrm{m}\). The block slides on a horizontal surface with a coefficient of friction of 0.2 . The block is displaced \(30 \mathrm{~mm}\) and released. How long will it take before the block returns to rest?