As the sound is one of types of fluctuations to change sound frequency, change the frequency of fluctuations of its source. Frequency of a sound more often call it height. Take a set of tuning forks and striking with a hammer them, make sure of different heights of a sound. The sound, the more frequency of fluctuations is higher. It is possible to change the frequency (height) of a sound, pulling or releasing a string. It is possible to change sound height also, using Dopler's effect.
It is required to you
- set of tuning forks, constant source of a sound, tense string.
Instruction
1. Change of frequency of a sound with the help kamertonovkazhdy of tuning forks reproduces a sound of a certain frequency. It depends on the frequency of fluctuations of its ends. Strike with a rubber hammer different tuning forks and determine by height of a sound where its frequency is higher and where below. It will change depending on the notes reproduced by a tuning fork.
2. Change of frequency of a sound you strunynatyanit a string on the resonator (it is possible to use a guitar). Pinch or blow force a string to hesitate. Change string tension force, watching sound frequency. At increase in force of a tension the sound becomes higher, and its frequency is more. At reduction of force of a tension of a string the sound becomes lower, and its frequency is less. Increase in frequency of a sound of a string in direct ratio to a root square tension forces (for example, having increased tension force by 9 times, we will receive increase in frequency three times). Replace a string with thinner, with a smaller weight and pull it with the same force, as previous. Having forced it to sound, make sure that with reduction of mass of a string the frequency of the sound given it increases. Frequency of fluctuations of a string is inversely proportional to a root square of its weight (for example if to reduce weight by 16 times, we will receive increase in frequency by 4 times). Let's take longer string and we will fix it on the resonator. With increase in length the frequency will decrease in proportion to a square root from value of length of a string.
3. Change of frequency of a sound with DopleraEsli's effect to move in relation to a motionless source of a sound, its frequency will change. Measure the speed of the receiver of a sound and learn the frequency of fluctuations of a source of a sound and speed of its distribution in the environment. To calculate new frequency, to number 1 add the relation of speed of the movement concerning the environment of distribution of waves to acoustic speed in this environment and increase result by the frequency of emission of a sound wave. If the source approaches the receiver, consider speed concerning Wednesday positive if it is removed – negative.