# Following a lecture on transverse and longitudinal waves, four students make Venn diagrams to characterize these waves.

## Question

Following a lecture on transverse and longitudinal waves, four students make Venn diagrams to characterize these waves.

Which Venn diagram is correct? (A) (B) (C) (D)

## Answer

B

Explanation:

Waves are periodic oscillations created by a disturbance, that travel carrying energy but not matter.

There exist two types of waves:

– Transverse waves: the direction of the oscillations is perpendicular to the direction of motion of the wave. These waves are characterized by the presence of crests (points of maximum positive displacement) and troughs (points of maximum negative displacement).An example of transverse wave are electromagnetic waves, which are produced by the oscillations of electric and magnetic field, and they are the only waves able to travel in a vacuum.

– Longitudinal waves: the direction of the oscillations is parallel to the direction of motion of the wave. These waves are characterized by the presence of compressions (regions where the particle density is higher) and rarefactions (regions where the particle density is lower). An example of longitudinal waves are sound waves.  Longitudinal waves are not able to travel trough a vacuum, but they travel faster in a denser medium.

We see that the correct Venn diagram that matches all the properties described above is diagram B.