You may be familiar with the idea of the period. Speed Wavelength x Frequency. Use the mode number n 1 and the string length L to calculate the wavelength of the standing wave.
The equation for wave speed can be used to calculate the speed of a wave when both wavelength and wave frequency are known.
Use the mode number n 1 and the string length L to calculate the wavelength of the standing wave. This whole back and forth motion makes one complete wave cycle. Speed Wavelength x Frequency. V f w Where V is the velocity ms.