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? a different kind of rock an underground lake an open cavity a pile of dinosaur bones

Explanation:

In general, sound (mechanical waves) travels faster in solids than in liquids, and faster in liquids than in gases. This is because the speed of the mechanical waves is determined by a relationship between the elastic properties of the medium in which they are propagated and the mass per unit volume of the medium (that is:density).

In other words: The speed of sound varies depending on the medium through which the sound waves travel.

So, if we are told the sound wave initially had a speed of 4,000 m/s and it suddenly decreases to 1,500 m/s, this means the sound waves passed from a solid medium to a liquid medium.

Hence, the correct option is: an underground lake.

kepler used the data from tycho blahe (his mentor) to construct the laws of planetary motion.

igneous rocks also form where plates converge. the subducting plate melts as it sinks into the crust of the earth, and the melt rises into the overriding plate forming volcanoes. metamorphic rocks are formed mainly in the lithosphere, wherever there is high pressure and high temperature. -woods