Question 37
SoundA man clapping his hands at regular intervals observes that the echo of a clap coincides with the next clap. If the reflecting cliff is 160 m away and the speed of sound is 320 m s−1, what is the frequency of the clapping?
- A.1 Hz
- B.2 Hz
- C.4 Hz
- D.8 Hz
Show the answer and explanation
Answer: A (1 Hz)
Explanation
The echo travels 320 m there and back in 320/320 = 1 s, so the claps are 1 s apart: 1 Hz.