Waves

A pipe closed at one end has length \(0.8 \mathrm{~m}\). At its open end \(0.5 \mathrm{~m}\) long uniform string is vibrating in its \(2^{\text {nd }}\) harmonic and it resonates with the fundamental frequency of the pipe. If the tension in the wire is \(50 \mathrm{~N}\) and the speed of sound is \(320 \mathrm{~m} / \mathrm{s}\), the mass of the string is