Validation linguists gained 84%, the design of 82.67%, 86.67% materials, and media gained 87.14%. Based on the stages that made learning media product obtained declared fit and is needed by learners after validating and testing the product. The research is the research and development method undertaken by several stages, a preliminary investigation, gathering information, product design, product validation, testing is limited to the user, and product revision. The study was conducted with the aim of producing instructional media products that meet the necessary criteria. Social media will be focused to develop is a media Instagram, in which can contain images and text content. One trend that is emerging now is the use of social media as a medium of learning. The development trend of technology and information at this time should be used by the world of education to make it as a learning tool, both outside and inside the classroom. The experiment can thus be used to assist high school students and physics undergraduates in understanding the inverse square law of sound or to study environmental noise with a simple and low-cost experiment. Higher frequency leads to a larger sound intensity. When the frequency of a source was changed (500 Hz, 1000 Hz and 2000), the sound intensity also changed. The results follow the theorem of which the sound intensity level at the detector depends on the distance between the source and the detector based on the inverse square law. The sound intensity level detected by the smartphone from 2,000 Hz resulted in the graph with smaller slope after passing 0.3 meters. Then, the sound intensity level versus distance was analyzed to determine the compatibility between the experimental results using a smartphone and the prevailing theory, namely the inverse square model.
In this study, the frequencies of the tone generator used were 500 Hz, 1000 Hz, and 2000 Hz. The smartphone functioning as the sound source was placed at a certain place labeled as the origin point (0.0), while the other smartphone as the detector was placed at various distances on the x-axis.
The type of this study was quantitative research by conducting level of intensity experiment using a pair of smartphones with one smartphone functioning as the sound source using a tone generator free application (app) and the other smartphone functioning as the detector installed with Physics Toolbox sound meter application to measure the arriving sound intensity level. The sound intensity in the car is 57.8 dB.The researchers present a simple experimental activity to measure the sound intensity level using an Android-based smartphone to prove the inverse square law and analyze the dependence of the sound intensity to the sound source frequency. Therefore, by putting on both layers of ear protection, the worker reduces the sound intensity by a factor of 3162.
The ratio of the full sound intensity to the reduced sound intensity the worker hears is approximately 3162. The ratio of the full sound intensity to the reduced sound intensity, expressed as Watts per meter squared is.
To identify which sound is which, they can be labeled with the index values 1 and 2: Using this mathematical formula for logarithms, the decibel formula can be rearranged to solve for I:
The mathematical formula for logarithms needed is: This problem can be solved by finding I for decibel values of 120 dB and 85.0 dB, and then dividing the full intensity by the reduced intensity. What is the ratio of the full sound intensity to the reduced sound intensity the worker hears?Īnswer: The decibel scale is logarithmic, and so a small drop in the decibel intensity means a much larger drop in the intensity expressed as. This reduces the intensity of the sound he hears from 120 dB to 85.0 dB. The sound intensity in the car is approximately 57.8 dB.Ģ) A worker uses double ear protection, both earplugs and earmuffs, to reduce the intensity of the sound of a jackhammer.
The intensity of the sound in decibels can now be found using the decibel formula: "Micro" means, and so the sound intensity in the car is: What is this sound intensity in decibels?Īnswer: The sound intensity in the car is expressed in micro-Watts per meter squared.