Question

In which of the following mediums, the speed of sound is maximum?
(A). Steel
(B). Wood
(C). Water
(D). Helium

Answer 1

Hint: Sound is a mechanical wave which propagates through vibrations. It requires a medium to travel and hence can travel in solids, liquids and gasses. The speed of propagation of sound is different in different mediums depending on the density of the medium. The energy of vibrations is transferred to other molecules in contact.

Complete answer:
Sound is a longitudinal wave which travels from one place to the other through vibrations. Sound needs a medium to travel, this means it cannot travel in a vacuum. The sound propagates as a combination of compressions and rarefactions through a medium.
Sound can travel in solids, liquids and gasses. Out of these, it travels fastest in solids as it travels by pushing the vibrations in the material forward. We can say that, the higher the density of a material, the faster is the speed of sound.
Thus, out of steel, wood, water and helium speed of sound will be fastest in steel and wood. Since, the density of steel is more than the density of wood as steel sinks in water while wood floats on water; speed of sound is maximum in steel.
Therefore, the speed of sound is the maximum in steel as it has the highest density.

Hence, the correct option is (A).

Note:
Longitudinal and transverse waves are two types of mechanical waves of which transverse waves can travel without a medium. Regions of high pressure are known as compressions regions of low pressure are called rarefactions. Sound propagates by transferring the energy of vibrations to the other molecules in contact.