Quarks?

I was asked is there anything smaller then a quark. Well that can be a tough question and to think it was posed by an 8 year old. This will be a very basic overview of the characteristics of a Quark. Quarks and the associated Leptons are complicated. This will be a basic overview and more questions are bound come from this so please ask me and we will learn together.

Lets start with what are Quarks and Leptons: Quarks and Leptons are the building blocks of matter.

Because they are so small they are normally referred to in cross section as that is a better way to understand them then by mass. But to give you an idea molecules are made of Protons, Neutrons and Electrons. One Proton is made of 3 Quarks. Quarks can be found in 6 different varieties and all have different characteristics or "colors"

But if you look at Leptons there are smaller particles called Neutrinos. These are referred to in experiments as: "the results are consistent with zero mass for the neutrino".

This is all part of Quantum Physics. As I stated before this is a complicated question with varied answers. The physicists have more questions then answers about these small particles that cannot be seen only their effects on each other is observed.

Please continue to explore this field and ask more questions. Below are a few links that I used to help my understanding.

http://www.madsci.org/posts/archives/2001-01/978636874.Ph.r.html

http://hyperphysics.phy-astr.gsu.edu/Hbase/Particles/lepton.html#c1

Speed of Sound

Does the speed of sound change with elevation?

Yes it does is the short answer but because I learned from my father that is never the way to answer here are the details.

The basic formula for finding the speed of sound is:

• R (287.05 J/(kg·K) for air) is the gas constant for air
• κ (kappa) is the adiabatic index (1.402 for air)
  
• T is the absolute temperature in kelvins

As can be seen by this the only thing that changes is temperature. As the temperature is lower the speed of sound is slower. This is the primary reason that sound is slower at higher elevations, the air is cooler there.

Just some examples the speed of sound at sea level is about 760 miles per hour and it is about 660 miles for an airplane.

Now what about sound through a solid object?

The stiffness and density of the material will affect the speed. Stiffness will will increase the speed and density will slow it down. This can make the calculations complicated. Here is the basic formula used to calculate the speed through solid materials:

C is a coefficient of stiffness

ρ is the density

There are other variations of this formula to calculate for liquids and gases.

Most of the information for this post was obtained from:

http://en.wikibooks.org/wiki/Acoustics/Sound_Speed

http://www.engineeringtoolbox.com/speed-sound-d_82.html

There is also a great slide show that has some examples and video of sound and speed: http://www.slideshare.net/darrella/speed-of-sound

Please post comments if you want clarification about any information in this posting or have any comments or questions.

Keep exploring your world.