PS-7.4   Use the formulas v = f λ and v = d/t to solve problems related to the velocity of waves.
Key concepts
Wave speed
Frequency - hertz
Wavelength
The relationship between wave velocity, wave frequency, and wavelength is defined mathematically by the following equation.
v = f λ 
In this equation "v" is wave velocity in m/s, "f" is wave frequency in Hertz, and the Greek letter lambda "λ" is wavelength in meters. 
The equation states, " the velocity of a wave is equal to the wave frequency times the wavelength. Here are several example problems using this equation. You should be able to solve the equation for any single variable when given the other two.
Q1: What is the frequency of a sound wave that has a wavelength of .5m and a velocity of 334m/s?
 
Here we are looking for the frequency and we are given the wave velocity and the wavelength.
f=v/λ      f= 334m/s /.5m       f= 668Hz