sound waves cause air particles to vibrate back and forth; ripples cause water particles to vibrate up and down. A longitudinal wave is one in which the vibrations of the particles are parallel to ...

A longitudinal wave is one in which the vibrations of the particles are parallel to the direction in which the energy of the wave travels. compressions are regions of high pressure due to ...

All motorcycle waves are truly a gesture to communicate support and camaraderie, often dedicated to just true motorcycles, from crotch-rockets to custom-built ones, versus something like a moped ...