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Science_Lab_Yellow / Lesson 1: What Makes Sound

What Makes Sound
What will we be learning today?

  • In this lesson, we are going to learn all about what makes sound.

What Makes Sound?

  • Sound is provided by making something move back and forth. You can't produce a sound without making something move. If you pluck a rubber band, the rubber band moving back and forth produces twanging sounds. This back-and-forth motion is called a vibration. Unless something vibrates, there can be no sound. Many vibrations are too fast for you to see. You may not see the bat vibrating when the ball hits it, but you can still feel it.

Energy Transfer

  • If you pluck a guitar string, you can see it moving back and forth. You provide the energy necessary for this vibration when you pluck it. This energy is transferred to the rubber band and causes it to vibrate. When you touch the rubber band, you can feel it vibrating.

  • What can you notice if you place your fingers gently against your throat while you talk or hum? You can feel a vibration. You feel the vibration of your vocal cords. Vocal cords in your throat vibrate when air moves past them, allowing you to speak.

  • What vibrates when you play a guitar? When the strings of a guitar or violin are bowed or plucked, they begin to vibrate. They produce sounds. However, not all instruments rely on strings. Sounds can also be produced by vibrating surfaces and by vibrating columns of air. The instruments in each section of the orchestra have their own characteristic ways of producing sounds. In each section different materials vibrate.

  • Sound Waves

    • Sound is a vibration that travels through matter. Matter is anything that has mass and takes up space. Matter can be a solid, liquid, or gas. Some types of matter are made of pieces too small to be seen, called molecules. Molecules are the smallest pieces that matter can be broken into without changing the kind of matter.

  • How does the sound made by a vibrating string travel? When a string vibrates, it makes molecules of gases in the air next to it vibrate. The molecules squeeze together, then spread apart. The vibrating molecules near the string then make the molecules next to them start to vibrate.

    • The vibration continues to spread. A vibration that spreads away from a vibrating object is a sound wave. It carries the energy from the vibrating object outward in all directions.

    Let's Review What We Learned Today!

    • Now go watch the movie "Waves"

    • Then complete your worksheet!