A mass of \(5 \mathrm{~kg}\) is attached to the top of a helical spring, and the system is made to vibrate by giving to the mass an initial deflection of \(25 \mathrm{~mm}\). The amplitude of the mass is found to reduce to \(10 \mathrm{~mm}\) after 100 cycles of vibration. Assuming a spring rate of \(200 \mathrm{~N} / \mathrm{m}\) for the helical spring, find the value of the hysteretic-damping coefficient \((h)\) of the spring.