5800 kilometers
A Pwave is the first wave to arrive during an earthquake, P waves compress and then expand. They can damage buildings.
The biggest seismic waves are surface waves, which travel along the Earth's surface and are usually the most destructive during an earthquake. The two main types of surface waves are Rayleigh waves and Love waves. Rayleigh waves cause the ground to move elliptically in vertical and horizontal directions, while Love waves cause horizontal shearing motion.
ECG records electrical activity and not mechanical, hence it has nothing to do with contraction. But P wave represents atrial depolarization.
p wave comes first s wave comes next and last comes surface wave.