Question

Two cars moving in opposite directions approach each other with speed of $22\, m/s$ and $16.5\, m/s$ respectively. The driver of the first car blows a horn having a frequency $400\, Hz$. The frequency heard by the driver of the second car is [velocity of sound $340\, m/s$] :

• A. 361 Hz
• B. 411 Hz
• C. 448 Hz
• D. 350 Hz

Answer 1

Answer: (C)

448 Hz

Answer 2

$f_{A} =f\left[\frac{v + v_{0}}{v-v_{s}}\right]$ $= 400\left[\frac{340+16.5}{340-22}\right]$ $f_{A} =448\, Hz$