NCERT Book Class 9 Science (Exploration) Chapter 10 Sound Waves: Characteristics and Applications

Chapter Sound Waves:
Characteristics and
10 Applications

Think It Over
Sound is an everyday sensory experience that helps us become
y Two astronauts are aware of our surroundings. Every day, we hear a variety of sounds
repairing the arm in our surroundings, such as human voices, birds chirping,
of a space station waves crashing on the seashore, leaves rustling, mobile phones
together during ringing, vehicles honking, music, and the claps of thunder. You
a spacewalk. Can have learnt in Chapter 7 that sound is a form of energy. You have
they talk to each also learnt that energy can neither be created nor be destroyed.
other and hear the It only changes from one form to another. Which form of energy
sounds of metal
gets converted to sound energy? How is sound produced and how
clanking as they do
on the Earth?
does it reach our ears? In this chapter, we will try to find the
answers to these questions.
y How do most bats
use sound to locate
their prey in the 10.1 Production of Sound
dark at night? You learnt a few ways to produce sound in
your textbooks for arts in the earlier grades.
Grade 3 Grade 4 Grade 5 Grade 6
Bansuri I Bansuri Bansuri Kriti I
Chapter 9 Chapter 13 Chapter 12 Chapter 7

Do you also remember learning about
Grade 7 sonority earlier, a property of some metals
Curiosity Fig. 10.1: Taal a
Chapter 4
where sound is produced when struck with
an object (Fig. 10.1)? musical instrument