A car moving at 30 m/s toward an observer sounds its horn at 400 Hz. If the speed of sound is 343 m/s, what frequency does the observer hear?
Correct answer: C. 436 Hz
- A. 368 Hz
- B. 400 Hz
- C. 436 Hz
- D. 472 Hz
Explanation
Explanation: Doppler effect: f' = f × (v / (v - vs )) = 400 × (343 / (343 - 30)) = 400 × (343 / 313) ≈ 436 Hz.
Last updated
Related questions
20 waves pass through a point in a medium, in 5 seconds. What is the time required for one wave to pass?
A 100 cm long string fixed at its two ends is plucked from the middle. The wavelength of stationary waves generated is:
A 100 cm long string fixed at its two ends is plucked from the middle. The wavelength of stationary waves generated is:
A 200 cm organ pipe with one end open is in resonance with a sound wave of wavelength 270 cm. The pipe is operating in its:
A cathode ray oscilloscope is displaying an AC signal. If one wave is completed in 20 cm along X- axis and time-base setting is 10 ms/cm, then frequency of AC signal will be: