Question

The driver of car travelling with a speed 30 meter/sec. towards a hill sounds a horn of frequency 600 Hz. If the velocity of sound in air is 330 m/s the frequency of reflected sound as heard by the driver is

• A. 720 Hz
• B. 555.5 Hz
• C. 550 Hz
• D. 500 Hz

Answer 1

Answer: (A)

720 Hz

Answer 2

This question is same as that of previous one so $n' = \frac{v + v_{car}}{v - v_{car}}.n = 720Hz$