a sound wave traveling downward with a speed of about 4,000 m/s suddenly slows to 1,500 m/s not far below…

a sound wave traveling downward with a speed of about 4,000 m/s suddenly slows to 1,500 m/s not far below the earths surface.\nwhat has the sound wave most likely encountered?\n○ a different kind of rock\n○ an underground lake\n○ an open cavity\n○ a pile of dinosaur bones

a sound wave traveling downward with a speed of about 4,000 m/s suddenly slows to 1,500 m/s not far below the earths surface.\nwhat has the sound wave most likely encountered?\n○ a different kind of rock\n○ an underground lake\n○ an open cavity\n○ a pile of dinosaur bones

Answer

Brief Explanations:

Sound waves travel at different speeds through different mediums. They slow down when moving from a denser to a less - dense medium. Rocks are denser than water in an underground lake or air in an open cavity. Dinosaur bones are not common near the Earth's surface and would not cause such a significant speed change. An underground lake or an open cavity would cause the sound wave to slow down. Since water in an underground lake is more likely to be encountered near the Earth's surface compared to a large open cavity, the sound wave most likely encountered an underground lake.

Answer:

an underground lake