You hear a song from your playlist you haven't heard in a while and it warrants you to commence singing. As you are sing, the power of the compression wave you create is approximately 579.05 nW (note, nW is nano-Watts). What is the intensity of this sound as measured by your roommate who is standing 9.89m from you? Please give your answer in units of nW/m2.
Properties of sound
A sound wave is a mechanical wave (or mechanical vibration) that transit through media such as gas (air), liquid (water), and solid (wood).
Quality Of Sound
A sound or a sound wave is defined as the energy produced due to the vibrations of particles in a medium. When any medium produces a disturbance or vibrations, it causes a movement in the air particles which produces sound waves. Molecules in the air vibrate about a certain average position and create compressions and rarefactions. This is called pitch which is defined as the frequency of sound. The frequency is defined as the number of oscillations in pressure per second.
Categories of Sound Wave
People perceive sound in different ways, like a medico student takes sound as vibration produced by objects reaching the human eardrum. A physicist perceives sound as vibration produced by an object, which produces disturbances in nearby air molecules that travel further. Both of them describe it as vibration generated by an object, the difference is one talks about how it is received and other deals with how it travels and propagates across various mediums.
You hear a song from your playlist you haven't heard in a while and it warrants you to commence singing. As you are sing, the power of the compression wave you create is approximately 579.05 nW (note, nW is nano-Watts). What is the intensity of this sound as measured by your roommate who is standing 9.89m from you? Please give your answer in units of nW/m2. This unit is not a common one. Usually, the unit would simply be Watts per square-meter (which would be your answer divided by a million!). This goes to show you that are ears are amazingly sensitive to very tiny sound intensities. Note: Intensity was a topic covered in section 11.1, and I will provide the formula: ?=?/?I=P/A where ?P is the power in units of Watts, and ?A is the surface area of a sphere of radius "L" (in this problem).
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