Question:
Which observation best supports the idea that sound is a mechanical wave?
(a) Sound shows reflection
(b) Sound needs a medium to propagate
(c) Sound has frequency
(d) Sound carries energy
Answer:
Verified
(b) Sound needs a medium to propagate
Explanation: Sound is called a mechanical wave because it requires a material medium such as air, water or solids for its propagation. Sound travels through the vibrations of particles of the medium. When a sound is produced, the particles of the medium vibrate and transfer energy from one particle to another. If there is no medium, such as in vacuum, sound cannot propagate.
