49.9k views
5 votes
A truck is traveling 70.0 kph away from you. The driver is blowing the horn, which has a frequency of 400 Hz. The air temperature is 25ÁC. What is the observed frequency of the horn?

2 Answers

5 votes

Answer:

the answer is 379 Hz

Step-by-step explanation:

User Herrtim
by
8.7k points
5 votes
There are several information's already given in the question. Based on those information's the answer can be easily deduced.
Speed of the truck = 70 kph
= 19.44 m/s
Speed of sound = 343 m/s
Then
Observed frequency = 400 Hz ∗ 343 m/s/19.44m/s + 343 m/s
= 378.54
= 379 Hz
User BenAlabaster
by
8.4k points