Which term describes energy transfer by a disturbance moving through a medium by particle vibration?

• A. Electromagnetic Waves
• B. Mechanical Waves
• C. Wavelength
• D. Diffraction

Answer: (B)

Energy transfer through a medium by a disturbance that makes the particles vibrate describes mechanical waves. In these waves, the energy moves through the material as particles wiggle back and forth or push and pull on their neighbors, passing the wave along without the matter as a whole traveling with the wave. This is why a sound wave in air or a ripple on a rope are mechanical waves—the medium (air or rope) is involved, and energy is carried by the patterned vibration of its particles. Electromagnetic waves, by contrast, can travel through empty space and don’t rely on vibrating particles in a medium. Wavelength is simply the distance between repeating points in the wave, and diffraction is about how waves bend around obstacles, not about how energy is transferred through a medium. So the correct concept here is mechanical waves.