What determines the propagation speed of ultrasound in a homogeneous medium?

What determines the propagation speed of ultrasound in a homogeneous medium?

• A. Density and elasticity
• B. Wavelength
• C. Amplitude
• D. Intensity & density

Answer: (A)

Propagation speed depends on how stiff the medium is and how much mass there is to move. A medium that resists compression (higher elastic modulus or bulk modulus) and has lower density will transmit ultrasound faster, because the medium can snap back quickly and offers less inertia to the moving wave. In fluids, this relationship is often written as speed ≈ sqrt(bulk modulus / density). So density and elasticity are the key determinants of how fast ultrasound travels in a homogeneous medium. Wavelength, amplitude, and intensity influence other aspects like resolution and signal strength, but they do not set the propagation speed.

Propagation speed depends on how stiff the medium is and how much mass there is to move. A medium that resists compression (higher elastic modulus or bulk modulus) and has lower density will transmit ultrasound faster, because the medium can snap back quickly and offers less inertia to the moving wave. In fluids, this relationship is often written as speed ≈ sqrt(bulk modulus / density). So density and elasticity are the key determinants of how fast ultrasound travels in a homogeneous medium. Wavelength, amplitude, and intensity influence other aspects like resolution and signal strength, but they do not set the propagation speed.