May.4th.2009

Mr. Manning did a homework check today on page 23. It was worth 5 points. Pablo asked him to review question number 2 so he did it on the smart board. After reviewing question number 2 on the homework, we did a daily question. Our daily question today was: A standing waves is produced in a tube 2 meters long. The tube has one open end and once closed (fixed) end. 1. Draw the standing wave in the 2 meter long tube if the 5th harmonic is sounded. 2. How long is 1 wavelength in the tube? Question number one's answer is represented by the picture and the answer to number 2 is 1.6 meters. Mr. Manning then did a demonstration with a swirly tube that was green and a motor connected to a pink string. He then did a demonstration with 2 tubes. One of them was filled with water while the other was opened on both ends. Then he used a tuning fork to produce sounds as he brought out the open eded tube(the one with no water). He used different tuning forks to get different pitches. Mr. Manning then did a demonstration using a orange bowling ball hanging from the ceiling from a white string. He started pushing the ball like the way you push someone on a swing set. He states that if you don't match the frequency you won't have the right amplitude. He did ANOTHER demonstration using 2 spheres hanging from 2 thin strings. It looked like a mini swing set, especially when they were swinging back and forth. All these demonstrations had to do with resonance.