wave_mechanics basics_of_mechanical_waves Question 36

Question: A man is standing between two parallel cliffs and fires a gun. If he hears first and second echoes after 1.5 s and 3.5s respectively, the distance between the cliffs is (Velocity of sound in air = 340 ms?1)

[EAMCET (Med.) 2000]

Options:

A) 1190 m

B) 850 m

C) 595 m

D) 510 m

Show Answer

Answer:

Correct Answer: B

Solution:

$ 2d _{1}+2d _{2}=v\times t _{1}+v\times t _{2} $

Therefore $ 2(d _{1}+d _{2})=v(t _{1}+t _{2}) $

$ d _{1}+d _{2}=\frac{v(t _{1}+t _{2})}{2} $ =$ \frac{340\times (1.5+3.5)}{2}=850 $ m.