A wave where particles vibrate in the same direction as energy transport is longitudinal. Sound waves exemplify this behavior. Therefore, the correct answer is (a) longitudinal.
The correct answer is option a. "Longitudinal".
Step-by-step explanation:
A longitudinal wave is characterized by particle vibrations that occur parallel to the direction of energy transport. In a longitudinal wave, the particles of the medium oscillate back and forth along the same axis as the wave is propagating.
On the other hand, in a transverse wave, the particles of the medium vibrate perpendicular to the direction of energy transport. This type of wave exhibits crests and troughs, and common examples include light waves and electromagnetic waves.
Sound waves, represented by option b, are indeed longitudinal waves. They propagate through the compression and rarefaction of particles in a medium, and the vibrations are in the same direction as the wave's movement.
Standing waves, as mentioned in option c, occur when two identical waves traveling in opposite directions interfere with each other. This creates points of no displacement called nodes and points of maximum displacement called antinodes.
In summary, if the particles of the medium are vibrating to and fro in the same direction as the energy transport, the wave is a longitudinal wave.