Can you tell the difference between electromagnetic and mechanical waves? In a mechanical or compression wave, the particles of the medium are displaced in a direction

perpendicular to the direction of energy transport.

A wavelength: in a transverse wave it can be measured from crest to crest; in a mechanical wave, from

compression to compression.

A thunderstorm! Lightning and thunder and rain! You hear the thunder before you see the lightning

because sound travels faster than light through the air.

Dolphins slap the wave to send messages because sound travels faster through water than through ain

Sound waves are transferred by the compression of particles. The closer the particles are to one another

the faster the energy is transferred. Therefore, sound energy directly depends upon the density of the

medium

Signals traveling through space must be in the form of electromagnetic waves rather than sound waves