What happens when the sound source is approaching the observer?
What happens to the frequency? Use the formula c=fλ
So, when the wavelength becomes smaller, the frequency becomes bigger
We can use this theory and a formula to calculate the apparent frequency of the source
We use the formula f'=\(\frac{v}{v±vs}\)f
When the source is moving away, we use a minus on the bottom of the fraction:
Just remember that the apparent frequency is going to be greater,
And check your answers, if you know the object is approaching but you get a smaller apparent frequency...