Waves

In an experiment with sonometer when a mass of \(180 \mathrm{~g}\) is attached to the string, it vibrates with fundamental frequency of \(30 \mathrm{~Hz}\). When a mass \(\mathrm{m}\) is attached, the string vibrates with fundamental frequency of \(50 \mathrm{~Hz}\). The value of \(\mathrm{m}\) is ___________ g.