The fundamental frequency of vibration of a string stretched between two rigid support is 50 Hz. The mass of the string is 18 g and its linear mass density is 20g/m. The speed of the transverse waves so produced in the string is ______ ms−1.
Answer: 90
Solution
The string length follows from ℓ=linear mass densitymass=2018=0.9m. In the fundamental mode the string carries a single loop, so λ=2ℓ=1.8m. The wave speed is v=fλ=50×1.8=90m s−1.