Asound wave traveling downward with a speed of about 4,000 m/s suddenly slows to 1,500 m/s not far below the earth’s surface. what has the sound wave most likely encountered? (its b) a. a different kind of rock b. an underground lake c. an open cavityd. a pile of dinosaur bones

Speed of sound wave depends on the elasticity of medium

It is given by formula

now if we are given that initially sound wave is travelling with speed 4000 m/s

Then its speed becomes 1500 m/s

so here since speed is decreased by large value

so here elasticity must decreased by large amount

A. a different kind of rock

B. an underground lake

C. an open cavity

D. a pile of dinosaur bones

So in above all options the density is changed or decreased by large value if the medium is changed to solid to liquid

So the correct answer will be

B. an underground lake

The sound wave most likely to be encountered in case of an underground lake. Hence, option (B) is correct.

Given data:

The initial speed of sound wave is, u = 4000 m/s.

The final speed of sound wave is, v = 1500 m/s.

Generally, the speed of sound wave depends on the density and the Elasticity of the medium. Then, the expression for the speed of sound is given as,

Here, E is the Elasticity of medium and is the density of medium.

Since, we are given the initial and final speed of sound wave as 4000 m/s and 1500 m/s. Clearly, there is huge drop in the speeds of wave, this may cause either there is huge increment in density of medium or huge decrement in the Elasticity of medium.

So in above all the given options the density is changed or decreased by large value if the medium is changed to solid to liquid. And this possible only in case of underground lake.

Thus, we can conclude that the sound wave most likely to be encountered in case of an underground lake. Hence, option (B) is correct.

Learn more about the sound wave here:

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