To develop this problem it is necessary to apply the concepts related to Wavelength, The relationship between speed, voltage and linear density as well as frequency. By definition the speed as a function of the tension and the linear density is given by
Where,
T = Tension
Linear density
Our data are given by
Tension , T = 70 N
Linear density ,
Amplitude , A = 7 cm = 0.07 m
Period , t = 0.35 s
Replacing our values,
Speed can also be expressed as
Re-arrange to find \lambda
Where,
f = Frequency,
Which is also described in function of the Period as,
Therefore replacing to find
Therefore the wavelength of the waves created in the string is 3.49m