Question

can you tell the difference between electromagnetic and mechanical waves? (choose 4)
a in a mechanical or compression wave, the particles of the medium are displaced in a direction perpendicular to the direction of energy transport.
b a wavelength in a transverse wave it can be measured from crest to crest; in a mechanical wave, from compression to compression.
c 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.
d dolphins slap the wave to send messages because sound travels faster through water than through air.
e 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.
f signals traveling through space must be in the form of electromagnetic waves rather than sound waves.

Explanation:

Electromagnetic waves can travel through a vacuum, while mechanical waves require a medium. In a mechanical compression wave, particles move parallel to the energy - transfer direction. Transverse waves have particles displaced perpendicular to energy transfer. Sound is a mechanical wave and its speed depends on medium density. Light is an electromagnetic wave and travels much faster than sound. Options A and B describe mechanical wave characteristics, option E describes sound as a mechanical wave, and option F differentiates between electromagnetic and mechanical waves in space - travel context.

Answer:

A. In a mechanical or compression wave, the particles of the medium are displaced in a direction perpendicular to the direction of energy transport.
B. A wavelength in a transverse wave it can be measured from crest to crest; in a mechanical wave, from compression to compression.
E. 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.
F. Signals traveling through space must be in the form of electromagnetic waves rather than sound waves.