Question

Which statement is true for particles of the medium of an earthquake P–wave?

They vibrate in a direction parallel to that of the wave, forming crests and troughs.

They vibrate in a direction parallel to that of the wave, forming compressions and rarefactions.

They vibrate in a direction perpendicular to that of the wave, forming crests and troughs.

They vibrate in a direction perpendicular to that of the wave, forming compressions and rarefactions.

Answer 1

the statement is true for particles of the medium of an earthquake P-wave is :
They vibrate in a direction parallel to that of the wave, forming compression and rarefaction
P-waves can be produced by earthquakes and recorded by seismographs.

Answer 2

I am pretty sure that the only statement which is true for particles of the medium of an earthquake P-wave is being shown in the option : b)vibrate parallel to the wave, forming compressions and rarefactions. As you know, it can be formed in two ways : from alternating compressions and rarefactions or primary wave. I bet you will agree with me.