Which statement correctly compares the speed of sound in air with soft tissue?

Which statement correctly compares the speed of sound in air with soft tissue?

• A. The speed of sound in air is greater than the speed of light.
• B. The speed of sound in air is greater than the speed of sound in soft tissue.
• C. The speed of sound in air is not predictable.
• D. The speed of sound in air is slower than the speed of sound in soft tissue.

Answer: (D)

Speed of sound depends on how easily the medium can be compressed and how stiff it is. In general, waves travel faster when the medium is stiffer and/or less dense, described by v ≈ sqrt(stiffness/density). Air is a light gas with low stiffness, giving a relatively small speed—about 340 m/s. Soft tissue, while denser, is much stiffer than air, and this higher elasticity dominates, pushing the speed up to around 1500 m/s. So sound moves much faster in soft tissue than in air, making the statement that air is slower than soft tissue the correct comparison.

Speed of sound depends on how easily the medium can be compressed and how stiff it is. In general, waves travel faster when the medium is stiffer and/or less dense, described by v ≈ sqrt(stiffness/density). Air is a light gas with low stiffness, giving a relatively small speed—about 340 m/s. Soft tissue, while denser, is much stiffer than air, and this higher elasticity dominates, pushing the speed up to around 1500 m/s. So sound moves much faster in soft tissue than in air, making the statement that air is slower than soft tissue the correct comparison.