NCERT Sound – Class 9 Science
The chapter “Sound” in NCERT Class 9 Science explains the nature, propagation, and characteristics of sound waves. Sound is a form of energy produced by vibrating objects and requires a medium (solid, liquid, or gas) to travel. Students learn about the longitudinal nature of sound waves, wavelength, frequency, and amplitude.
The chapter also explores concepts such as speed of sound in different mediums, reflection of sound (echo), and reverberation, which are important in acoustics. Phenomena like sonar and ultrasonics are also discussed to highlight practical applications in navigation, medical imaging, and detecting underwater objects.
Furthermore, the chapter explains the human ear structure and how sound is perceived, helping students understand hearing mechanisms. By studying this chapter, Class 9 students grasp both theoretical and practical aspects of sound, forming a foundation for advanced topics in Physics and everyday applications of sound in technology and communication.
