SOLAR SYSTEM

Detailed explanation-1: -P waves travel fastest and are the first to arrive from the earthquake. In S or shear waves, rock oscillates perpendicular to the direction of wave propagation. In rock, S waves generally travel about 60% the speed of P waves, and the S wave always arrives after the P wave.

Detailed explanation-2: -Secondary waves, or S waves, are slower than P waves. The motion of secondary waves is perpendicular to the direction of the wave travel, similar to the motion of vigorously shaking a rope (SF Fig.

Detailed explanation-3: -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. P-waves are compression waves that apply a force in the direction of propagation.

Detailed explanation-4: -In air, P waves take the form of sound waves and therefore move at the speed of sound, 330m/s at sea level. Some people even report hearing an earthquake (due to the higher frequency P waves vibrating or rustling objects) before they feel the S waves’ arrival.