Question

In which medium the speed of sound will be maximum?
1. Water
2. Copper
3. Steel
4. Aluminium
5. None of the above/More than one of the above

Answer 1

Correct Answer - Option 4 : Aluminium

Concept: 

• Speed of Sound in a Medium: The speed of sound in a medium is decided by the density of that material, temperature and elasticity.
• The Sound wave is a type of longitudinal mechanical wave which propagates only through a medium by vibrating the molecules of its particle. 
  • If molecules are compact, the sound waves can propagate faster. 
  • Solid having molecules compact together. So usually, speed of sound is more in Solids compared to liquids and more in liquid than gases. 

Explanation:

Medium	Speed of sound (m/s)
Gases
Air (0° C)	331
Air (20° C)	343
Helium	965
Hydrogen	1284
Liquids
Water	1402
Water	1428
Seawater	1522
Solids
Copper	3560
Steel	5941
Granite	6000
Aluminium	6420

 

• The above table shows the speed of sound in solids > speed of sound in liquids > speed of sound in gases — although the densities of solids and liquids are much higher than those of the gases.
• This is because liquids and solids are less compressible than gases i.e., liquids and solids have much greater bulk modulus than that of gases.
• Thus, the speed of sound decreases when we go from solid to a gaseous state.

 

Therefore the speed of sound is maximum in Aluminum than other options available.