Volume , or loudness, is related to the strength, intensity, pressure, or power of the sound. There are a few ways of varying the volume of a tuning fork. Touching the vibrating fork to a table after being struck produces a louder sound.
When both the table and the tuning fork vibrate, more air molecules are moved than by the tuning fork on its own. Touching a vibrating fork to clothes or your hand causes a damping effect on the vibrations reduction in size and the sound disappears. The energy from the vibrating fork is converted to moving your skin or clothes rather than moving air.
Resonance is the tendency of an object to vibrate at maximum amplitude size at a certain frequency. This frequency is known as the object's resonant frequency. Acoustic sound resonance is an important consideration for instrument builders, as most acoustic instruments use resonators think of the box of a guitar or a violin, or the hollow body of a drum.
Describe the properties of sound. Per Class: tuning forks rubber mallet or the rubber bottom of a shoe resonance box optional.
If using this as an activity, provide the materials above for each pair of students. Why do different sized tuning forks produce different sounds? If you know frequency of each fork, can you tell me how many times per second each fork will vibrate? How can we increase the volume of a tuning fork? How can we decrease the volume of a tuning fork? Details Activity Length 10 mins. Sound waves are longitudinal waves. Their vibrations occur in the same direction as the direction of travel.
Sound waves can only travel through a solid, liquid or gas. When an object or substance vibrates, it produces sound. The bigger the vibrations, the greater the amplitude and the louder the sound. A microphone converts sound energy into electrical energy in the form of electronic signals. A computer or an oscilloscope can be used to display these electronic signals, which show the same changes in amplitude and frequency as the sound waves.
When these signals are observed on the oscilloscope, the oscilloscope pattern will indicate the same changes in amplitude and frequency which correspond to the wave's loudness and pitch frequency. Again, we have used some shorthand notation.
If the period is rather small, we don't want to keep writing lots of zeros after the decimal point, so we use scientific notation, instead. This is especially convenient for sound waves, as the periods of sound waves are generally around 1 to msec. Consider the Earth going around the sun. Is this motion repetitive? What would an oscillation correspond to?
What is the period and frequency of the motion? Repetitive sounds can be formed in different ways. The most common, of course, is from a musical instrument. But, now, consider the situation where you are standing in front of a set of bleachers and you strike a bass drum:.
The individual echoes of the drum off each step are delayed from one another. So, to the drummer the echoes form a repetitive sound which then is heard as a pitch. Anyone who has played in a marching band can attest to this! Besides the pitch of a musical note, perhaps the most noticeable feature in how loud the note is.
The loudness of a sound wave is determined from its amplitude. While loudness is only associated with sound waves, all types of waves have an amplitude. Waves on a calm ocean may be less than 1 foot high.
0コメント