Page 72 - Science Course 3 (Book 2)

Understanding Sound Mo10-L4a: How are Sound Waves
Produced?
Lesson 4

The region where molecules are closer together is a
compression.

In this topic, you will learn the following
lessons:
Mo.10–L4a: How are Sound Waves Produced?

Mo.10–L4b: How Do you Hear Sounds?

Mo10–L4a How are Sound Waves Produced?

KEY CONCEPTS:
1. How are sound waves produced?
2. Why does the speed of sound waves vary in
different materials? Drumhead moves Up

Vocabulary A-Z The region where molecules are farther apart is a

Let us learn some vocabulary rarefaction.

sound wave

a longitudinal wave that can travel only through
matter.

Let’s Begin

What is Sound? Drumhead moves Down

A sound wave is a longitudinal wave that can travel Molecules that
only in matter. make up air

Vibrations produce sound waves by moving
molecules in air.

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