Science Unit Two: Sound

Hello people it is me ethant36 and today I will tell you about my second science unit: sound.

What is sound?

The first thing I will tell you about is what is sound. Sound is a series of vibrations that cause sound. The 4 properties of sound are: Sound can be reflected (echoes). Sound can be absorbed, too. It is absorbed with soft materials.  Sound can be modified (speakers modify sound). Finally, sound is caused by vibrations.

                           Vibrations

You cannot always see the vibrations but they are vibrating. Sometimes with watches you can make it vibrate (you can feel that sometimes!) but if it is making sound it is vibrating. One fun experiment: The materials you need are sour cream container or anything like it, tuning fork, salt, plastic wrap, rubber band, and water. Instructions: 1. put the plastic wrap over the container tightly with the rubber band.

                           Absorbing sound

Here is a picture of a recording room. The foam absorbs the sound so there is almost no echo. The foam on the wall is amazing for absorbing sound. They do not want movies to sound weird.

Echoes

Echoes are sound being reflected. Echoes bounce of of surfaces and you can sometimes hear the word again. Concrete and hard materials like it echo more than soft materials, which absorb sound.

Pitch

Pitch is how high the sound is. It is measured in Hertz (Hz) humans can hear sounds from 20hz to 20 000hz. Dogs can hear higher sounds than humans which is why humans can not hear. Dolphins and bats can hear even higher sound than dogs.

 

               Here is a picture of my model ear:

Here is a video on how ears work

 

 

 

 

 

 

 

Volume

Volume is how loud a sound is. Volume is measured in decibels (dB). A whisper is about 30dB a normal voice is about 60 dB and a scream is about 120dB. If people are around noises over 90dB all the time their hearing can be damaged and if a human hears a sound over 130dB their hearing can be damaged immediately.

 

Reflection of learning

I liked the sound unit and I liked the experiment.

 

Hope you liked it!