# Science reciprocal of period. So something with high

Science Inquiry ProjectBy Dakotta Baillargeon and Max FauthKilbourne Middle School, Science 7        Table of ContentsAbstract……………………………………………………………………………. 3Research Question………………………………………………………………. 4 Literature Review…………………………………………………………………. 5Hypothesis………………………………………………………………………… 9Experimental Design…………………………………………………………….. 10Observations……………………………………………………………………… 12Conclusion………………………………………………………………………… 13Bibliography………………………………………………………………………. 14Appendix………………………………………………………………………….. 15Acknowledgements……………………………………………………………….16AbstractResearch QuestionWhich of five different types of drums will generate the highest frequency? Literature ReviewFrequency refers to the number of vibrations that an individual particle makes in a specific period of time.  No matter what is causing the vibrating, the particles in a solid through which the sound moves is vibrating back and forth at a given frequency.  Frequency is how often particles pass through a medium and the act of them doing so. “The frequency of a wave is measured as the number of complete back-and-forth vibrations of a particle of the medium per unit of time” The measurement for this is hertz.  One hertz= 1 vibration per second.  When sound waves go through an object, they all are at  the same frequency.  That is sensible because each particle follows in its neighbors actions.  Of course there must be a first particle to vibrate.  The rate at which the medium vibrates will apply to the air particles too. For example if a guitar is vibrating at 500 particles per second then the air particles would be vibrating at 500 Hertz.Sound is a pressure wave.  Because of this, a detector should be used to detect oscillations in pressure from a high pressure to a low pressure to high again.  The frequency also refers to the number of compressions or rarefactions that pass through a solid at a certain time.  The human ear can detect frequencies anywhere from 20 Hz to 20,000 Hz.  Anything detected by a human at less than 20 Hz is called infrasound.  Anything detected by a human more than 20,000 Hz is called ultrasound.  Dogs can detect from 50 to 45,000 Hz.  Cats can detect from 45 to 85,000 Hz.  Bats can detect as high as 120,000.  Dolphins can detect as high as 200,000 Hz.  Elephants, however, have an uncanny ability to hear infrasound, as they detect frequencies as low as 5 Hz.Sound is caused by the molecules of a medium vibration.  The frequency of a wave is different from the speed of a wave.  This sensation of frequency is known more commonly as pitch.  A high pitch sound has a high frequency.  A low pitch sound has a low frequency.  This means that high pitched sounds have low period.  Also, it means that low pitched sounds have a high period.  Frequency is the reciprocal of period.  So something with high frequency would have less period on a pressure time plot. That means something with low frequency would have a high period, and something with a high frequency has a low period.  The image below shows a high frequency wave while the bottom image shows a low frequency waveParticles vibrate at a specific frequency for each material/object called its natural frequency.  Resonance is when objects with the same natural frequency as the vibrating object also begin to vibrate.  Speed = frequency * wavelength.  Sound travels at 343 meters per second at standard temperature and pressure.  The fundamental frequency emitted by a drum is determined by f=2.405*(T/m)^(1/2)/(2*pi*r) where T is the tension and m is the mass per unit area and r is the radius of the membrane.  The pitch and of the drum also depends on the tension of the skin adjusted by the turnkeys.  The bass drum is said to have no definite pitch.  The larger the drum the lower fundamental frequency emitted and vise versa.  The type of skin on the drum effects the fundamental frequencyThe height of the wave is its amplitude.  Amplitude determines how loud a sound will be.  There  can be two kinds of interference patterns, constructive and destructive.  Constructive interference is when two waveforms are added together.  Destructive interference occurs when two waves are out of phase. Hypothesis If the different drums are hit at the same force to see which will have the highest frequency, then the bass drum will have the highest frequency.Hypothesis If the different drums are hit at the same force to see which will have the highest frequency, then the bass drum will have the highest frequency.Experimental DesignMake sure the drum is in tuneHit the drumMeasure the frequencyWrite down observations in observations sectionWrite down thoughts in observations sectionRepeat for other four drumsMaterials ListMaple 5a vic-firth drumstickRemo snare drum Tom 1 Tom 2 Floor tom Bass drumRose gold Iphone 6sYamaha hardwareSpectrum appDakotta BaillargeonMax Fauth The experiment was done because if you’re in a band, you want a wide variety of sounds (more likely good ones), especially from your percussion section.  So the scientists decided to find out which percussion instrument in a drum set will have the highest frequency (or the highest hertz level).  They think it will give them knowledge about how and why percussion instruments are used not just in orchestras and marching bands, but touring bands as well.In the scientists experiment, the independent variable was the certain drum the scientists used.  The dependent variable, however, was the hertz level that the particular drum gave off.  The scientists controlled variable was the rate at which they hit the drum.  They controlled the rate at which they hit the drum by using a tool that hits an object with the same force.  The scientists changed the independent variable by switching from different drums.  They measured the dependent variable by seeing what the hertz level was for each drum and writing it down.ObservationsTest one: bass drumHertz peak: 80 hzThoughts: Surprisingly low hertz level but to early to tellTest two: snare drumHertz peak: 234 hzThoughts: Way higher than expected but a snare drum can play higher than a whole band.  Still a bit too early to tell.Test three: tom 1Hertz peak: 240 hzThoughts: This was completely unexpected.  I have nothing else to say.Test four: tom 2Hertz peak: 193 hzThoughts: finally something decreased in hertz but it’s still surprisingly high when I said bass drum was going to have the highest hertz level.Test five, final test; floor tomHertz peak: 154 hzThoughts: Going down more but I’m still in awe of how the bass drum had the lowest.Final thoughts: This experiment went in the opposite direction of what I thought.  I thought that the bass drum was going to be in first but it came in last.  Even more shocking is the fact that it was in last by a mile!  However, I did overlook the fact that a snare drum can play over an entire band.Conclusion So, what really happens when drums are tested for their frequency?  Well, the scientists hypothesis was very wrong, as the drum that he predicted to get first got last.BibliographyWorks Cited”The Physics of Sound.” The Physics of Sound – The Method Behind the Music, method-behind-the-music.com/mechanics/physics/.”Pitch and Frequency.” The Physics Classroom, www.physicsclassroom.com/class/sound/Lesson-2/Pitch-and-Frequency.education.com. “Changing the Pitch of Sound | Science Project.” Science Project | Education.com, Jan. 2014,Appendix”The Physics of Sound.” The Physics of Sound – The Method Behind the Music, method-behind-the-music.com/mechanics/physics/.Drum typeBassSnareTom 1Tom 2Floor tomHertz level80234240193154AcknowledgmentsMs. FedMr. AlexisMr. AaronMs. Baillargeon