Vibrations and Sound

The physical phenomena that promotes hearing is sound. Some sounds, like thunder, the sound of the ocean crashing on the coast, and the wind in the trees, happen naturally, but others are created specifically for a particular reason. Vibrations are what produce all sounds.  Air molecules are compressed closer together by the moving item before being stretched apart. The energy wave is transmitted by these molecules pulling and then pushing the ones just next to them, and so on. Hence, a sound wave is a collection of undetectable compressions and expansions that ripple through the air.  

When the atomic building blocks of a substance—or atoms linked together to form molecules—move back and forth, sound can pass through the material. Every atom or molecule collides with another before returning to its initial place. The energy is transferred from one to the next as though via a chain of links, yet the atoms or molecules themselves merely shift a small distance away from their primary locations. Although we often think of sound as a wave, it actually consists of regions where particles are closer together and farther apart, rippling outward from the source. Regions of high and low air pressure make up these air ripples. The wave loses a tiny amount of energy each time the particles collide. As a result, when you get further away, the wave gradually gets smaller.

Let us conduct an experiment showing vibrations produced along with sounds.

The Ringing Spoon 

Air in motion is all that actually makes up sound, and our ears are what allow us to detect that air in motion. A vibrating sound is made when an object is moved vigorously.
 

Learning Objectives: 

With the help of this experiment, the students will be able to:

• make observation, ask questions,test their own hypotheses  and explain about how sound is made.

Resources: 

1. string
2. rubber band 
3. metal spoon

Procedure:

Cut a 2 inch piece of string off.

At the middle of the thread, fasten a metal spoon with a rubber band.
 

The string's ends should be wrapped around your fingers.

Place your fingers in your ears while leaning against a table and move your body back and forth.

The spoon should tap against the table's edge.

Explanation: 

The spoon starts to vibrate when it makes contact with something or taps against the table. Your fingers, the string, and your ears are all vibrated as a result. The air vibrates as a result, sending "sound" to our ears. The sound waves go directly along the string and are brought right into your ears when we attach the strings to this and tap them into your ears. The vibrations are picked up by your eardrums and sent to your brain, where they are turned into what the brain interprets as sound. When compared to air, sound travels more effectively through solids like the spoon and string.

 

Questions for discussion:

1. What is sound? How does it produce?

2. How does vibration affect the sound we hear? 

3. Give some examples of natural sounds and man made sounds.