Question

An ambulance driver traveling at 31.0 m/s (69.3 mph) honks his horn as he sees a motorist ahead on the highway traveling in the same direction. The motorist hears a frequency of 392 Hz and notices that his own speedometer reads 44.7 mph (20.0 m/s). Calculate the frequency that the ambulance driver hears. (Speed of sound is 340 m/s) (in Hz)

Answer 1

Answer:

fo = 378.52Hz

Explanation:

Using Doppler effect formula:

$f'=\frac{C-Vb}{C-Va}*fo$

where

f' = 392 Hz

C = 340m/s

Vb = 20m/s

Va = 31m/s

Replacing these values and solving for fo:

fo = 378.52Hz