Here's why:
* Longitudinal Waves: In these waves, the particles of the medium vibrate back and forth *parallel* to the direction the wave travels. Think of a spring: if you push one end, the compression (disturbance) travels down the spring, and the coils of the spring move back and forth in the same direction as the wave.
* Transverse Waves: In contrast, in transverse waves, the particles of the medium vibrate *perpendicular* to the direction the wave travels. Imagine a rope tied to a pole: if you shake the rope up and down, the wave travels along the rope, but the rope itself moves up and down.
Examples of longitudinal waves:
* Sound waves: Sound travels through air as a series of compressions and rarefactions (areas of high and low pressure).
* Seismic P-waves: These waves are the fastest type of seismic wave and travel through the Earth's interior, causing the ground to move back and forth.
