Explanation: \(\text{Hints: } \omega = 2\pi f = \sqrt{\frac{k}{m}}\) \(\text{Solve: } \frac{f_1}{f_2} = \sqrt{\frac{m_2}{m_1}} = \sqrt{\frac{2m}{m}} = \sqrt{2} = 1.4\) \(\therefore f_1 = 1.4f_2 \, \text{অর্থাৎ } 1.4 \, \text{গুণ কমবে।}\) \(\text{Ans. (D)}\) \(\text{ব্যাখ্যা: } \omega^2 = \frac{k}{m} \implies \omega = \sqrt{\frac{k}{m}} \implies 2\pi f = \sqrt{\frac{k}{m}} \implies f = \frac{1}{2\pi}\sqrt{\frac{k}{m}}\) \(\therefore f_1 = \frac{1}{2\pi}\sqrt{\frac{k}{m_1}}, \, f_2 = \frac{1}{2\pi}\sqrt{\frac{k}{m_2}}\) \(\implies \frac{f_1}{f_2} = \sqrt{\frac{m_2}{m_1}}\)