Ultrasound

Definition

Ultrasound is sound waves with frequencies above the upper limit of human hearing, typically above 20 kHz. It is used in medical imaging and industrial applications.

5 Must Know Facts For Your Next Test

1. Ultrasound waves have frequencies higher than 20 kHz, beyond the hearing range of humans.
2. It is widely used in medical diagnostics, particularly for imaging internal organs and monitoring fetal development.
3. In physics, ultrasound can be used to study properties of materials through techniques like ultrasonic testing.
4. The speed of ultrasound waves depends on the medium through which they pass, being faster in solids than in liquids and gases.
5. Doppler ultrasound is a special type of ultrasound that can measure the flow of blood or other fluids.

Review Questions

• What is the frequency range for ultrasound?
• How does the speed of ultrasound waves vary with different mediums?
• What are some common applications of ultrasound in medicine?

Related terms

Frequency:

The number of wave cycles that pass a point per unit time, measured in Hertz (Hz).

Doppler Effect:

A change in frequency or wavelength of a wave relative to an observer moving relative to the source of the wave.

Acoustic Impedance:

$Z = \rho c$, where $\rho$ is density and $c$ is speed of sound; determines how much sound is reflected at a boundary between two media.