Which statement about speed in the body is true?

Which statement about speed in the body is true?

• A. It is exactly 1,540 m/s in all tissues
• B. It ranges from 500 to 4000 m/s depending on tissue
• C. It is the same for fat and liver
• D. It is independent of tissue

Answer: (B)

Speed of sound in the body depends on the tissue’s physical properties, mainly density and compressibility (elasticity). Because these properties vary widely among tissues, the speed of sound is not the same everywhere. In soft tissues, it’s typically around 1540 m/s, but in denser, stiffer tissues like bone it can be much higher—up to about 4000 m/s—while in softer or more compressible tissues it can be lower, around a few hundred to a thousand m/s. This explains why the speed is described as ranging from roughly 500 to 4000 m/s depending on the tissue. Understanding this variation helps in applications like ultrasound, where travel time is used to infer distances.

Speed of sound in the body depends on the tissue’s physical properties, mainly density and compressibility (elasticity). Because these properties vary widely among tissues, the speed of sound is not the same everywhere. In soft tissues, it’s typically around 1540 m/s, but in denser, stiffer tissues like bone it can be much higher—up to about 4000 m/s—while in softer or more compressible tissues it can be lower, around a few hundred to a thousand m/s. This explains why the speed is described as ranging from roughly 500 to 4000 m/s depending on the tissue. Understanding this variation helps in applications like ultrasound, where travel time is used to infer distances.