4-24-09+Karley+Kolb

Schedule for the day- · Collect ride calculations and design · Notes on sound · JSM video · More notes on sound Homework for the weekend- NONE (finish week 2 roller coaster project if you didn’t have it on Friday) Summary- Mr. Manning showed us a strobe light demo which showed us the vibrations in a tuning fork. He held the fork next to the strobe light which made it easy to see the frequency of each. After that he showed us a wood instrument with only one hole in it. He explained that the only way to get a different pitch out of the instrument is to either shorten or elongate it. He told us the shorter the instrument is the higher the pitch, and the longer the instrument the lower the pitch. We then learned through the JSM video that in order to have a sound we need to have a vibrating system. We also learned that if something has a higher frequency it has a higher pitch (lower frequency lower pitch). He then demonstrated with a pair of speakers the highest frequency that is audible to the human ear and the lowest. He also had us walk around the room to see where there was destructive inference (softer sound) and where there was constructive inference (louder). Mechanical behavior = frequency. The above picture is demonstrating the vibrations in the tuning fork. He stuck the fork and pressed it against the table so we could hear it better. He explained that the shorter the tuning for the higher the pitch. This is because the smaller tuning fork has less surface area than a longer fork.