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?

Question

Physics

Trent Haas

28 December, 21:45

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?

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Answers (1)

Know the Answer?

Lizeth Levy · Answer 1

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