Which statement correctly describes sound energy?

Which statement correctly describes sound energy?

• A. Sound is electromagnetic energy.
• B. In a medium, sound is mechanical energy transmitted by longitudinal pressure waves through an elastic medium.
• C. Sound is always audible.
• D. Sound travels faster in vacuum.

Answer: (B)

Sound energy is a form of mechanical energy carried by waves that propagate through matter as alternating regions of compression and rarefaction. In a medium, these waves are primarily longitudinal pressure waves, with particle motion parallel to the direction of travel, transmitted by the elastic forces of the material. This is why sound requires a medium to travel and is not electromagnetic energy. It cannot move through vacuum because there are no particles to carry the pressure variations. Additionally, not all sound is audible; frequencies outside the human hearing range exist. The speed of sound depends on the medium’s stiffness and density, being faster in stiffer, less dense media and slower in denser or softer ones.

Sound energy is a form of mechanical energy carried by waves that propagate through matter as alternating regions of compression and rarefaction. In a medium, these waves are primarily longitudinal pressure waves, with particle motion parallel to the direction of travel, transmitted by the elastic forces of the material. This is why sound requires a medium to travel and is not electromagnetic energy. It cannot move through vacuum because there are no particles to carry the pressure variations. Additionally, not all sound is audible; frequencies outside the human hearing range exist. The speed of sound depends on the medium’s stiffness and density, being faster in stiffer, less dense media and slower in denser or softer ones.