MP Board Book for Class 9th Science Chapter 12- Sound

This chapter is related to the class 9th MP board. The name of this chapter is sound. In this chapter we will learn many useful definitions that are-

Sound is mainly produced through the vibration of various objects.
Production of sound, propagation of sound, sound needs a medium to travel, sound waves are longitudinal waves, characteristics of sound wave, speed of a sound in different medium, reflection of sound, echo, uses of multiple reflections of a sound, range of hearing, application of ultrasound, sonar, structure of ear.
Sound travels as a longitudinal wave through a material medium.
Sound is a mechanical wave which needs a material medium like air, water, steel etc for its propagation.
Sound propagates through a medium at a finite speed.
Reflection of sound travels at the same speed as if it travels towards the surface.
The audible range of sound for human beings extends from 20hz to 2000hz.
Ultrasounds are high frequency waves.
Sound cannot travel in vacuum.
The speed of the sound depends primarily on the nature and temperature of the transmitting medium.
Sound properties such as pitch, quality and loudness, quality are determined by the corresponding wave properties.
Loudness is a physiological response of the ear to the intensity of sound.