How does the medium move in relation to the direction of energy transport in a longitudinal wave?

perpendicular
parallel
side-by-side
or underneath ?
please answer asap!

Question

How does the medium move in relation to the direction of energy transport in a longitudinal wave?

perpendicular
parallel
side-by-side
or underneath ? 
please answer asap!

kropot72 · Answer

If you think of sound waves in air, the medium (air) moves as layers of compression and rarefaction in the same direction as the wave. So which of the choices in your question would apply to such sound waves?

kropot72 · Answer

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The above diagram might help you. The sound wave is a longitudinal wave.

anonymous · Answer

Parallel