Sound and Matter

Lesson Plan - Get It!

Audio:

Throughout the Related Lessons in this All About Sound series, found in the right-hand sidebar, you have been learning how sound is formed and how it moves so it can be heard.

Take a minute to refresh your memory.

• How is sound formed?
• How does it move?

If you said sound is formed by vibrating matter, you are correct!

• Sound travels in waves called compression waves, but did you know that sound moves differently through different types of objects?

In the previous lessons, you learned that the average speed of sound is around 760 miles per hour, but this speed can vary depending on what type of media, or phase of matter, the sound is traveling through.

Look at the pictures at the beginning of the lesson again. The balloon represents gas, the bag of water represents liquid, and the sandcastle represents a solid.

• Which phase of matter do you think sound can travel through with the most ease?

Print the Sound and Matter Experiment from Downloadable Resources in the right-hand sidebar. Write your prediction in the section labeled "Hypothesis."

Complete an experiment to determine the answer to this question. Use the Sound and Matter Experiment worksheet as your guide and to record your data. You will need the following materials to complete the experiment.

• three sandwich bags
• sand or soil
• water

When setting up the bags for the experiment, squeeze out as much air as possible from your solids and liquids bags. Now, complete the "Experiment" and "Conclusions" sections of the worksheet.

• Which media allowed the sound to travel the best in your experiment?

You should have found that sound travels best through solids. This is because the molecules in a solid are packed tighter together, allowing the molecules to bump into each other and vibrate more.

Sound has the most difficulty traveling through air or gasses. This is because air molecules are loosely spread out, making it difficult for the molecules to vibrate and bump into each other.

To learn more about the relationship between sound and matter, watch the video below. It will review what you have learned about compression waves and illustrate how sound travels through different media.

• Did the results of your experiment turn out correctly?
• Could you hear the tapping sound best through the sand or the soil?

If your experiment had a different outcome, consider what you might have done differently or repeat the experiment. Then, when you are ready, move on to the Got It? section to review what you have learned about sound and matter.