Physics pres. madlib
- 1. BYOP: Waves By: CJ and Jesus
- 2. Standards we will be covering 1. Waves can be transverse or longitudinal 2. Visual representation to construct an explanation of the differences in transverse and longitudinal waves by focusing on the vibration that generates the wave. 3. Relationship between wave speed, wavelength and frequency 4. Standing waves - nodes, antinodes, reflections, boundary conditions
- 3. Our Experiment CJ being a violin player and Jesus being a guitar player, we decided to explore why different instruments produce differing sounds even when playing the same note We discovered that we hear the same fundamental frequency as the pitch, but the different instruments do not produce the same harmonics
- 4. Our Experiment (cont.) We then wondered, why do the instruments create the same fundamental frequency, but different harmonics? There are many reasons to why this occurs: Different bodies - A guitar body is much larger than that of a violin, and it is structured differently, creating different vibrations Instruments are constructed from different materials. Jesus’ electric guitar has strings made of metal, whereas violins can have metal or nylon strings. Different materials create different sound The violin is played with a bow, which may impact the sound produced
- 5. How do stringed instruments work? The vibrations of the strings on the instrument displace air molecules to create sound The vibrations of the strings alone are not enough, since the strings displace very small amounts of space However, when attached to a longer object, such as the body and neck of a guitar, the strings displace more air The strings cause the body of the instrument to begin vibrating at the same frequency as the string, and the body of the instrument sends air molecules in motion, creating sound
- 6. Understanding Waves on String Instruments Standing waves are produced when a string is plucked by the vibration reaching the end of the string and reflecting back the other way (we see this as the string moving up and down or vibrating back and forth) There is a place among the string where the string is actually not moving, or the displacement of the string is actually zero, these are referred to as nodes Inversely, there is a place on the string in which the string has moved its maximum amount producing the amplitude on the soundwave, where the displacement of the string is greatest, this is referred to as antinodes
- 7. Transverse Waves in music A transverse wave is produced when when the oscillations of the wave form right angles with the direction the wave is traveling, in other words the vibration of the string is perpendicular to the direction it is traveling. A longitudinal wave is produced when the oscillation of the wave are parallel to the direction the wave is travelling; similar to a slinky type motion.
- 8. Transverse Waves in music (cont.) When a string is played on an instrument, it displaces the air molecules around it with vibrations The vibrations caused by the string being plucked are caused by transverse waves Once the air molecules are vibrating to create sound, the sound waves, as all sound waves, create longitudinal waves
- 10. Wavelength, frequency, and pitch Wavelength is how long a wave is Longer waves oscillate slower, that is what causes the waves to be longer The wavelength of a wave determines the frequency - the frequency of the particles of air moving when a wave passes Longer wavelength = Lower frequency Shorter wavelength = Higher frequency Frequency is measured in Hertz (Hz) Pitches are measured in Hertz
- 13. Japan