Nature & Properties of Sound Waves

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Nature & Properties of Sound Waves

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Think Pair Share

Discuss with your partner what you saw in the video.

Draw a conclusion for how you think the flame was able to be extinguished, or put out, with only a human voice.

Nature of Sound Waves

When an object, like a radio speaker or guitar string vibrates, it collides with nearby particles in the air, transferring some of the energy to them.

The process of collisions & energy transfer forms a sound wave.

Nature of Sound Waves

What type of mechanical wave are sound waves?

Longitudinal/compressional waves~ compress and expand as they travel.(Think of the movement of a slinky toy as it transfers energy.)

Nature of Sound Waves

Sound waves are mechanical waves~ they require a medium through which to travel.

What do footsteps sound like on the moon?

Nature of Sound Waves

On the moon, there is no atmosphere and therefore no particles for energy to transfer. No matter = no sound waves.

How can astronauts

communicate in space?

Behavior of Sound Waves

Behavior of sound waves: Sound waves can be reflected~ sonar uses reflected sound waves to detect objects underwater.

Nature of Sound Waves

Can sound waves travel through solids, liquids, and gases?

Yes, solids, liquids, and gases carry sound waves.

Speed of Sound Waves

With the knowledge that sound waves need particles in order to transfer energy, Think Pair Share with your partner to answer the following question:

In what material~ solid, liquid, or gas, do sound waves travel the fastest? The slowest?

Speed of Sound Waves

Which material allows sound waves to travel faster?

TRY THIS: knock gently on the top of your desk.

Now, press your ear against the top of your desk and knock gently.

Speed of Sound Waves

What did you notice or observe about the sounds you heard?

What inference can you make about why this occurred?

Speed of Sound Waves

When particles are closer together, such as in liquids and especially solids, energy is transmitted quicker. Therefore, the speed of sound waves depends on the material it is passing through.

Bucket Brigade!

Speed of Sound Waves

Medium Speed of Sound (in m/s)

Air 347Cork 500Water 1,498Brick 3,650Aluminum 4,877

Speed of Sound Waves

Speed does NOT depend on loudness~loud and soft sound waves travel at the same speed.

Think Pair Share

Discuss with your partner the Essential Question: What causes sound waves and how do they travel?

Write a one-sentence statement to answer this question and post it on my office door when you are dismissed.