Sound is a ______ wave in which particles in the medium move.

Sound is a ______ wave in which particles in the medium move.

• A. Electromagnetic
• B. Mechanical
• C. Thermal
• D. Acoustic

Answer: (B)

Sound is a mechanical wave because its energy travels through a material medium by the actual vibration and movement of the particles in that medium. As the wave passes, particles oscillate around their rest positions, creating regions of compression and rarefaction that push neighboring particles and hand the motion along from one particle to the next. This required motion of matter distinguishes it from waves that don’t need a medium, like electromagnetic waves, which propagate through changing electric and magnetic fields. While acoustic is another term often used for sound, the essential idea described here is the way the medium’s particles move, which is characteristic of mechanical waves.

Sound is a mechanical wave because its energy travels through a material medium by the actual vibration and movement of the particles in that medium. As the wave passes, particles oscillate around their rest positions, creating regions of compression and rarefaction that push neighboring particles and hand the motion along from one particle to the next. This required motion of matter distinguishes it from waves that don’t need a medium, like electromagnetic waves, which propagate through changing electric and magnetic fields. While acoustic is another term often used for sound, the essential idea described here is the way the medium’s particles move, which is characteristic of mechanical waves.