wavelength
When working with waves ... or even just talking about them ... (frequency) = (speed) divided by (wavelength) (wavelength) = (speed) divided by (frequency) (frequency) times (wavelength) = (speed)
frequency for apex learners not speed :)
The speed or velocity of a wave is equal to the wavelength times the frequency. The period (amount of time for one wavelength to occur) is equal to 1 over the frequency (the inverse of its frequency).
Frequency.
The product of (wavelength) times (frequency) is equal to the speed of the wave.
(wavelength) x (frequency) = wave speed
Divide the speed by the wavelength. (For any wave, the wavelength times the frequency is equal to the speed of the wave.)
Wavelength = (speed) divided by (frequency) Frequency = (speed) divided by (wavelength) Speed = (frequency) times (wavelength)
Speed = (frequency) times (wavelength) Frequency = (speed) divided by (wavelength) Wavelength = (speed) divided by (frequency)
The product of (wavelength) times (frequency) is the speed.
Convert the cm to meters, to have compatible units. Then use the fact that the frequency times the wavelength is equal to the speed of the wave. In this case, you can divide the speed by the wavelength, to get the frequency.
The speed of a wave is equal to its wavelength times its frequency. Since you are using SI units, the answer will be in meters/second.