Question

Two factories are sounding their sirens at 800 Hz. A man goes from one factory to other at a speed of 2 m/s. The velocity of sound is 320 m/s. The number of beats heard by the person in one second will be

• A. 10
• B. 2
• C. 8
• D. 4

Answer 1

The correct option is A 10

Answer is A , Number of beats, b is

$b=\frac{2V_{o}n}{V_s}=\frac{2\times 2\times 800}{320}=10$