Sound facility

Sound light and colour   

🤣Full oppen your eyes and listen carefully🤣

How many sound can you here? Some might be loud; others might be quiet. Have you even wondered how sounds are actually produced? Can the booming of an explosion, the soft clicking of you fingers and the sound of drums beating, all be made the same way? Surprisingly, the answer is yes.

Look at this picture of a stone falling into still body of water. The rings of waves expand outward in circles

Vibrations produce sound waves

Just like light and electricity, sound is also a form of energy. It is produced by vibrations and travels in waves. When an object hits the surface of water, the waves travel outward in a circle. Sound waves too travel outward in circles, but we cannot see them.

Irregular, repetitive sound waves create noise, while regular repetitive waves produce musical notes. 

Sound moves through the air by pushing the air particles around its source. When an object vibrates, it move air particles around it. These air particles bump into one another. They are squashed and then they expand as each one of them passes on its energy to the next one. The vibrations passing from molecule to molecule are called sound waves. If your ear is within the range of the vibrations, you can hear the sound.

Sound waves are vibrations that cannot be seed.

Can sound be measured?

Can we find out how many sound waves strike against our ears? 

Sounds can be measured by counting the vibrations made in a second. The number of vibration per second is called the frequency. We measure the vibrations or frequency by using special units called hertz (hz). This unit tells us how many vibrations there are per second.

Low sounds are produced when there are few vibrations per second. High sound are produced when there are more vibrations per second.

Most humans can here sounds ranging between 20 hertz and 16,000 hertz.

Different animeals have different hearing ranges.

  

                                 Explain

 When the vibrations are fast, you hear a high note. When the vibrations are slow, it creates a low notes. If you pluck the string of a guitar, it begins to vibrate. 

The vibrations disturb the air around the string and sound waves are produced. 

If the string is plucked with force, a loud note is produced. If the string is plucked gently, a soft note is produced. 

Can you tell which of  the sound waves shown below is showing high frequency and which one is showing low frequency? 

 Sound need a medium to travel through 

In outer space these is complete silence. Sound cannot travel through outer space because it is a vacuum that contains nothing to carry sound. 

The air through which sound travel is called a medium. 

A  medium can be anything' a liquid such as water, a solid such as the wall, or a gas such as air. Sound travels fastes in solids, then in liquids and most slowly in gases. 

Echoes 

 

A sound made in a large, empty room produced an echo.

An echo is produced when sound waves bounce off surface. When there are many objects in the room, or there are lots of soft materials like clothes, cushions, ect., the sound waves are absorbed and do not bounce back. 

 A bat uses echoes to tell where it is going. It make high-pitched, squeaking sounds. These sounds bounce off abjects and back to the bats each .

Dolphins also use sound waves to find their way in the sea.

Ships have special equipment on board to send out sound waves to show their location, especially in foggy weather.