What is the approximate speed of sound in water?

What is the approximate speed of sound in water?

• A. 343 m/s
• B. 1480 m/s
• C. 1500 m/s
• D. 5000 m/s

Answer: (B)

Sound speed depends on how compressible and dense a medium is. Water is relatively incompressible and has a moderate density, so pressure waves travel quickly. Using the relation c ≈ sqrt(B/ρ) for a liquid, with water’s bulk modulus B around 2.2 x 10^9 Pa and density ρ about 1000 kg/m^3, gives c ≈ sqrt(2.2 x 10^6) ≈ 1.48 x 10^3 m/s. So the speed is about 1500 m/s in water, much faster than in air (about 343 m/s) but not as high as in solids.

Sound speed depends on how compressible and dense a medium is. Water is relatively incompressible and has a moderate density, so pressure waves travel quickly. Using the relation c ≈ sqrt(B/ρ) for a liquid, with water’s bulk modulus B around 2.2 x 10^9 Pa and density ρ about 1000 kg/m^3, gives c ≈ sqrt(2.2 x 10^6) ≈ 1.48 x 10^3 m/s. So the speed is about 1500 m/s in water, much faster than in air (about 343 m/s) but not as high as in solids.