P -waves travel faster because the movement of them, it is a back and forth motion while S- waves are a side to side expending more energy.
The P-wave which is a form of body wave known as a compression or longitudinal wave.
P waves travel faster than S waves. P waves use less energy to travel, while S waves have to use more. This is because P waves travel in a forward and back motion such as a push and pull motion. S...
They are called primary waves.
EV Wave at 2009 NY International Auto Show
Hundreds Dead as 8.9 Quake, Tsunami Rock Japan
Media Analyzes Economic Impact of Japan Quake
Catching up on the Wave - Overview of Google Wave - #5