More Waves!

We got more into waves and learned about sound waves! We learned that sound waves are specific kinds of waves (longitudinal waves (areas of compression and refraction)) and that sound waves need a medium to go through. All sound travels at the same speed relative to temperature. So if the temperature is hotter sound waves will travel faster and if the temperature is colder sound waves will travel slower. A good example of this concept is that on the mainland the speed of sound is about 340 m/s but here in Hawaii where it's warmer the speed of sound is about 343 m/s. We also learned about three main key concepts. First, refraction or the changes in wave direction and speed due to changes in medium. Second, natural frequency or the frequency an object will vibrate with after an external disturbance. Finally third, resonance or the increase in amplitude or oscillation or an electric or mechanical system exposed to a periodic external force whose frequency is equal to or some multiple of the natural frequency.

This is a picture from a scrapbook from when my family went on a trip to Florida in the summer when I was in about 5th grade. It was crazy because pretty much everyday just when it started to get dark huge thunder and lightning storms would role in and there'd be huge flashes and sounds everywhere. We see lightning before thunder because the speed of light is faster than the speed of sound, so you can estimate how far away the lighting is touching the ground by counting the number of seconds between the time you see the lighting and when you hear the thunder. The general rule is that every three seconds equals about one kilometer and five seconds equals about 1 mile.