Question

Sound travels the fastest in which of the following mediums?
(a). Water
(b). Steel
(c). Air
(d). Kerosene oil

Answer 1

- Hint: Sound travels faster in solids than any other states.

Complete step-by-step solution -

Sound travels faster in Steel than any other liquids. In steel, the density and elastic properties are more than other given mediums. Hence the option (B) is correct.

ADDITIONAL INFORMATION:

For gases, the sound moves only when the collision of molecules happens. This will create the condensations and rarefactions. Temperature is also affecting the speed of sound in air. In liquids, sound travels faster than in gases since the molecules are tightly packed. As we know several aquatic animals are living and communicating with the help of sound. For solids, sound travels very fast than any other state. In solids, molecules are very close together than any other states. In steel sound can travel 17 times faster than through air. However, some exceptional solids are also there.
The closest molecules and tighter bonds will take less time for the passage of sound. Velocity of sound wave is affected by two main properties of matter; density and elastic properties. Following equation shows that relation where $$\rho$$ is the density and $$C_{ij}$$ is the elastic properties of the matter.
$$v=\sqrt{{\displaystyle \frac{C_{ij}}{\rho }}}$$
Solid density is very high than the liquid and gaseous state. Moreover, the steel exhibits great elastic properties. Both of these functions make steel a better option for the fastest sound travelling medium.
Generally, the velocity of the sound increases in the order of vacuum medium < gaseous medium < liquid medium < solid medium.

Note: Steel is a rigid material and it experiences smaller deformations, hence it is having large elastic properties. The density is also higher for steel. Both of these properties have a great impact on the speed of the sound.