Question

When both source and listener are approaching each other the observed frequency of sound is given by ($V_L$ and $V_S$ is the velocity of listener and source respectively, $n_0 = \text{radiated frequency}$)

• A. $n=n_{0}\left[\frac{V+V_{L{V-V_{s\right]$
• B. $n=n_{0}\left[\frac{V-V_{L{V+V_{s\right]$
• C. $n=n_{0}\left[\frac{V-V_{L{V-V_{s\right]$
• D. $n=n_{0}\left[\frac{V+V_{L{V+V_{s\right]$

Hint:

Logic Tip: Approaching = higher pitch. To get a higher frequency $n$, the fraction multiplier must be greater than 1. This means maximizing the numerator ($+$) and minimizing the denominator ($-$). Thus, $\frac{V+V_L}{V-V_S}$ is the only logical choice!

Answer 1

The Correct Option is A