sound energy By Daniel

Transcription

1 sound energy By Daniel

2 What makes sound? How does sound travel? Sound was made when sound is provided by making something move back and forth. You can`t produce a sound without making something move. If you pluck a rubber band, the rubber band moving back and forth produces twanging sounds. Unless something vibrates, there can be no sound. Sound travels when a string vibrates, it makes molecules of gases in the air next to it vibrate. The molecules squeeze together, then spread apart. A vibration that spreads away from a vibrating object is a sound wave. It carries the energy from the vibrating object outward in all directions.

3 What can sound go through? Sound can go through you when sound waves reach your ear, they make parts inside the ear vibrate. Since air is a mixture of gases, you may conclude that sound can travel through gases. If someone taps the table at the other end, you can hear the tapping louder than if you lift your head away from the table. You can hear someone calling you from above the surface.

4 What is pitch? How can you change the pitch on a stringed instrument? How does frequency affect pitch? Pitch is how high or low a sound is. I can change the pitch on a stringed instrument by if you pluck a rubber band to make sounds, than you can change the pitch by shortening the rubber band. A second way you can change the pitch is to stretch the rubber band tighter. This cause the rubber band to vibrate faster and, therefore, to produce a higher-pitched sound. Frequency affect pitch when the higher the pitch, the more squeezed together the waves are.

5 What is volume? How does energy affect volume? Volume is how loud or soft it is depends on the amount of energy in a sound wave. To make a louder sound with a rubber band, pluck it harder. Energy affect volume when a loud sound has more energy than a soft sound and produces a taller wave on an oscilloscope. You can also make a sound louder by increasing the amount of surface that vibrates.

6 Describe how reflection and absorption affect sound. Give real-world examples of sound reflection and absorption. Reflection and absorption affect sound when a sound wave is absorbed, its energy is changed into heat energy. Designing concert halls has always been a tricky business. To get the right sound, engineers try to get a good balance of reflection and absorption. Too much reflection results in an empty, hollow sound. Too much absorption deadens the music.

7 What is echo? Give real-world examples of some places that would create a strong echo and why it creates a strong echo. Echo is a related sound wave. Some places that would create a strong echo are if you sing in the shower, you may notice how rich your voice sounds. The hard, smooth walls of the bathroom are often great for making echoes. The echoes reflect back and forth off the walls many times. It creates a strong echo because if the echo is strong enough, you will hear yourself yelling hello! after you said it! If there is more than one reflecting surface near you, you may hear hello! several more times.

8 What is echolocation? Give some real world examples of things or animals that use echolocation. Echolocation are many animals find things around them with a form of sonar. Things or animals that uses echolocations are whales and dolphins bounce sound waves off objects to find out how far away they are. Bats are able to live in dark caves because they use a form of echolocation rather than sight to navigate. Bats send out high-pitched squeals and clicks into the air at their prey.

9 Describe the Doppler Effect. Give a real world examples of this. Doppler effects are the change in frequency (and pitch) as a source of sound moves toward or away from you. It is named for the 19 th century Austrian scientist Christian Johann Doppler, who first described it. Many radar (radio detection and ranging) devices use the effects to find the speed of objects. Patrol cars detect changes in frequency as a way of detecting speeding vehicles.

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