Answer
a) 4 meters
b) 14 Hz
Work Step by Step
a) We find the longest wavelength by simplifying the equation for L:
$ \lambda = \frac{2L}{m}=\frac{2\times 2}{1}=4m$
The lowest frequency corresponds to the longest wavelength. Thus:
b) $f = \frac{56}{4} = 14\ Hz$
