P wave is body waves that propagate through the planet. P-waves travel 60% faster than S-waves on average because the interior of the Earth does not react the same way to both of them.
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P-waves are compression waves that apply a force in the direction of propagation. As the interior of the Earth is almost incompressible, P-waves transmit their energy quite easily through the medium and thus travel quickly.
Why do P wave travel faster than S wave?
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When an earthquake occurs, it releases energy in the form of seismic waves that radiate from the earthquake source in all directions. The different types of energy waves shake the ground in different ways and also travel through the earth at different velocities. The fastest wave, and therefore the first to arrive at a given location, is called the P waves( Primary Wave ).
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The P wave, or compressional wave, alternately compresses and expands material in the same direction it is traveling. The S wave( Secondary Wave ) is slower than the P-wave and arrives next, shaking the ground up and down and back and forth perpendicular to the direction it is traveling. Surface waves follow the P-waves and S waves.