Sound is amazing. The world would be very quiet if there was no sound. Here are some fun facts about sound.

Basics of Sound

Sound Waves

 There are two types of sound waves, transverse and longitudinal. The difference is longitudinal-the wave are traveling parallel (like wiggling a string back and forth) and transverse-when the wave vertically points perpendicular (light or radio waves).

Graphic representation of a sound wave

Figure 1: Graphic representations of a sound wave. (A) Air at equilibrium, in the absence of a sound wave; (B) compressions and rarefaction that constitute a sound wave; (C) transverse representation of the wave, showing amplitude (A) and wavelength (λ). Encyclopædia Britannica, Inc.

Wave Altitude

The height of the wave measured in volume or energy.

Wave Frequency

You have to see how many waves occur per second.

Wavelength

A measurement that measures from peak to adjacent peak or a trough to adjacent trough.

Relationship between frequency and wavelength

As frequency increases wavelength decreases.

Pulse wave is a wave form that includes square waves and similarly periodic waves.

Harmonic waves are a variation with position at one time.

Wave Absorption and Transmission

Wave absorption goes through a medium such as water, the sound gets absorbed, so then it is harder to hear the sound anymore, like noise cancelling headphones except this is water.

Wave transmission you can hear because it has more vibrations than water so you can hear better when the sound is transmitted rather than absorbed.

How do you determine the speed of sound?

The peaks or the speed of any single point on the wave shape to figure out a formula for the velocity of sound.

Speed = wavelength * frequency

Speed of Sound

Speed of sound =767 miles per hour

You have to break the sound barrier to go into space. The first person on earth to break the sound barrier was Chuck Yeager on October 14, 1947 in an airplane he named after his wife.

The speed of sound has to be the wavelength of the wave divided by the period of the wave. The speed of sound means the rate at which the disturbance is moved through the air molecules.400 × 400

Changing the Speed of the Sound

To change the speed of sound, you will have to change the temperature or the density of the room you are in.

The wave has to overlap the initial shape after the period because the molecule has to be back where it started after one period.

Displacement of air molecules

We can see as the wave travels, the shape travels to the right in the picture below.

“Seeing” Sound

Voices produce sound wave. As an example, the picture here is the sound wave of me saying my full name. You can see that there is only one place where there is no sound, so my first and middle name run together.

Here is an audio recording of me saying the Pledge of Allegiance.

Here is the picture of what that looks like.

Notice how they are all different shapes. If we could see sound, then we would probably see this everyday because we say the Pledge everyday.

Conclusion

This is how amazing Sound can be. You can use sound for many things. But don’t use it too brutally.

References

Our notes from class

http://www.brittanica.com

http://www.youtube.com/watch?v=UgE2GIQwUCw&feature=youtu.be.

https://www.explainthatstuff.com/sound.html

space.com/26204-chuck-yeager.html

Ultrasonics – Sound – Effect of Speed of Sound on Wavelength