Compression and rarefaction are two phenomenon occurs in longitudunal wave!
when there is denser particle gathering in that wave , there we called it compression and the rarer part of particles is rarefaction !
<span>The Appalachian Mountains were formed when colliding tectonic plates folded and upthrust, mainly during the Permian Period and again in the Cretaceous Period. The folds and thrusts were then eroded and carved by wind, streams and glaciers. These erosive processes are ongoing, and the topography of the Appalachian Mountains continue to change. They have changed with the miles of land that are cleared of all vegetation and topsoil. In the 1970's coal miners literally blow away the top of a mountain to get to the coal underneath.</span>
The answer is A. The Sun and all the planets revolve around Earth.
Aristotle believed that the Earth was the centre of the solar system, and the Sun and the planets orbited around it. He believed that the universe was composed of Earth-like bodies, which were at rest, and of heavenly bodies, which were in perpetual motion.
I’m pretty sure 14 is mutations
Answer:


Explanation:
In order to calculate the equivalent spring constant we need to use the next formula:

Replacing the data provided:


Finally, to calculate the frequency of oscillation we use this:

Replacing m and k:
