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EMMI PIETARILA 8TH GRADE

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Presentation on theme: "EMMI PIETARILA 8TH GRADE"— Presentation transcript:

1 EMMI PIETARILA 8TH GRADE
SOUND WAVES

2 Leonardo Da Vinci Sound wave was discovered back in the Leonardo Da Vinci’s (1452–1519) era. He discovered that sound travels in waves. He was a brilliant artist, scientist, and thinker and contributed many discoveries in the field of science.  He was a man before his time who thought up inventions and ideas that came to be built far later by other engineers and scientists.

3 Christian Doppler Christian Doppler later discovered that sound waves could be compressed or expanded, thereby, further expanding on da Vinci’s theory. Sound waves have been rethought and the theory re-analyzed by many scientists throughout the years. 

4 What does it travel through?
Although it is commonly travelling in air, sound can travel through many materials, such as water and steel. Some insulating materials absorb sound waves. Because sound is the vibration of matter, it does not travel through a vacuum or in outer space. When you see movies or TV shows about battles in outer space, you should only be able to see an explosion but not hear it. The sounds are added for dramatic effect. Sound waves are different than light waves Electromagnetic waves, like radio and light are completely different than sound that are vibration of matter.

5 … . … . … … . . … . … Characteristics of sound A sound wave has the same characteristics as the other wave forms. It has a wavelength, frequency, type of velocity and amplitude. Wavelength is the distance from crest to another of a wave. Because sound is a compression wave, the wavelength is the distance between maximum compressions. Speed or velocity A sound wave moves about 344 meters/sec, feet/sec.

6 Making s0und Whenever an object in air vibrates, it causes longitudinal or compression waves in the air. These waves move away from the object as sound. There are many forms of the vibration. When you speak, your vocal cords also vibrate, creating sound. Blowing across a bottle top can also create sound. In this case, the air inside the bottle goes in a circular motion, resulting in sound waves being formed. Wind blowing through trees can also create sound this indirect way. The back and forth movement of a guitar string or drum head result in compression waves of sound. Sound can also be created by vibrating an object in a liquid such as water or in a solid such as iron. A train rolling on a steel railroad track will create a sound wave that travels through the tracks. They will then vibrate, creating sound in air that you can hear, while the train may be a great distance away.

7 Detecting S0und When a sound wave strikes an object, it can cause the object to vibrate. This leads to the method to detect sound, which requires changing that vibration into some other type of signal—usually electrical. The main way you detect or sense sounds is through your ears. The sound waves vibrate your ear drum, which goes to the inner ear and is changed to nerve signals you can sense. You can also feel sounds. Stand in front of a stereo or hi-fi loudspeaker on at full volume, and you can feel some of the vibrations from the music. There are mechanical devices that detect sounds, such as the microphone. The sound vibrates a membrane, which creates an electric signal that is amplified and recorded.

8 5 Interesting facts When traveling through water, sound moves around four times faster than when it travels through air Dogs can hear sound at a higher frequency than humans, allowing them to hear noises that we can’t. The sound of thunder is produced by rapidly heated air surrounding lightning which expands faster than the speed of sound. Sound is used by many animals to detect danger, warning them of possible attacks before they happen. The speed of sound is around 767 miles per hour (1,230 kilometres per hour)


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