Unit 9 Waves and Sound

My picture is of Beats headphones because headphones represent sound and we learned about sound yesterday. We first learned a lot of terms: 

Reflection is the bounding of waves an example is echoes. Refraction is the bending of waves due to changes in wave medium an example is waves at a beach. Dispersion is the spreading out of waves. A standing wave is a wave that looks like its not moving. Natural (resonant) frequencies are the frequencies that an object wants to vibrate at specific depends on physical qualities of an object. Resonance is the increase in amplitude of a system exposed to a force at an objects natural frequency. Ex. a glass shattering after rubbing the top/ vibration, kidney stones and a twisty bridge. Sound itself is a longitudinal wave and needs a medium to travel through. Sound travels fasted in solids, then liquids then gases. Pitch is the frequency of the sound. All frequencies of sound travel at the same speed and temperature, but do not travel at the same medium. 

Yesterday we completed a lab involving a tuning fork. We would hit 5 different tuning forks with different frequencies against our shoe or a harder object, resulting in the tuning fork making a noise. Then we would hold it to a tube that was in a cylinder of water and pull the tube up with the tuning fork until the tuning fork make a loud noise. We would record down the length of the tube from the water then calculate wavelength (x4 the length) and the wave speed (the wave length x the frequency).