Velocity can be calculated using the following rule: velocity = lambda * frequency where: velocity is given = 6 km/sec lambda is the wavelength that we want to calculate frequency is given = 13 Hz
Substitute with the givens in the above equation to get the wavelength (lambda) as follows: 6 = 13*lambda wavelength = 6/13 = 0.461538 Km = 461.538 meters
