wave_mechanics basics_of_mechanical_waves Question 32

Question: The echo of a gunshot is heard 8 sec. after the gun is fired. How far from him is the surface that reflects the sound (velocity of sound in air = 350 m/s)

[JIPMER 1999]

Options:

A) 1400 m

B) 2800 m

C) 700 m

D) 350 m

Show Answer

Answer:

Correct Answer: A

Solution:

Suppose the distance between shooter and reflecting surface is d.

Hence time interval for hearing echo is $ t=\frac{2d}{v} $

Therefore $ 8=\frac{2d}{350} $

Therefore $ d=1400m $ .