Applications of ultrasound (sound waves with frequencies greater than 20,000 Hz) as described in the NCERT Class 9th Science book include uses in industry and medicine, as well as in nature.
Industrial Applications
- Ultrasound is used for cleaning objects in hard-to-reach areas by placing them in a cleaning solution and sending ultrasonic waves into it, which detach dirt particles.
- It is also used to detect cracks and flaws in metal blocks without causing damage.
Medical Applications
- Echocardiography: Creates images of the heart using reflected ultrasonic waves.
- Ultrasonography: An instrument using ultrasonic waves to produce images of internal organs like the liver, gall bladder, uterus, and kidneys. This helps doctors identify abnormalities such as stones or tumors and examine a fetus during pregnancy for defects.
- Ultrasound can break down kidney stones into smaller grains for easy removal.
In Nature and Navigation
- Bats use ultrasound for navigation and locating prey through echolocation.
- Dolphins also utilize ultrasound to find fish and avoid predators.
- SONAR employs ultrasonic waves to determine the distance, direction, and speed of underwater objects, as well as the depth of the sea.