Question

While sitting in your car by the side of a country road, you are approached by your friend, who happens to be in an identical car. You blow your car’s horn, which has a frequency of 260 Hz. Your friend blows his car’s horn, which is identical to yours, and you hear a beat frequency of 6.0 Hz. How fast is your friend approaching you?

Answer 1

Answer:

7.85m/sec

Explanation:

definition of terms

speed of sound is 340m/s

sound is an example of wave source

speed is change in distance per time

Perceived frequency of friend's horn = 266Hz.

beat=f1-f2

6=f1-260 Hz

f1=266Hz.

we make an assumption that the velocity of sound will be used, I will adopt 340m/sec.

$V_{0}$=340m/sec.

$(V_{0} *f_{1}/f_{2})-V_{0}$

(340 x 266/260)- 340 = 7.85m/sec

my friend will be approaching me at that speed