The basic relationship between frequency, wavelength and speed of a wave is given by [tex]v=\lambda f[/tex] where v is the wave speed f is its frequency [tex]\lambda[/tex] is its wavelength
Re-arranging the equation and using the data of the problem, we find the frequency of the wave: [tex]f= \frac{v}{\lambda}= \frac{65 m/s}{0.8 m}=81.3 Hz [/tex]
