Agong makes a loud noise when struck. the noise gradually gets less and less loud until it fades below the sensitivity of the human ear. the simplest model of how the gong produces the sound we hear treats the gong as a damped harmonic oscillator. the tone we hear is related to the frequency f of the oscillation, and its loudness is proportional to the energy of the oscillation.

part a if the loudness drops to 80 % of its original value in 4.0 s , what is the time constant of the damped oscillation?

part b how long does it take for the sound to be 20 % as loud as it was at the start?

part c what fraction of the original loudness remains after 1.0 min?

so here is the information for current research:

-nrel's geothermal analysts, scientists, and engineers perform a full range of research from developing advanced methods of locating and accessing geothermal resources to exploring innovative technologies to extract and produce clean energy from the heat of the earth

and here is the information for the technology of geothermal energy:

-it's clean and sustainable

-resources of geothermal energy range from the shallow ground to hot water and hot rock found a few miles beneath the earth's surface, and down even deeper to the extremely high temperatures of molten rock called magma

-almost everywhere, the shallow ground or upper 10 feet of the earth's surface maintains a nearly constant temperature between 50° and 60°f (10° and 16°c)

-geothermal heat pumps can tap into this resource to heat and cool buildings

-a geothermal heat pump system consists of a heat pump, an air delivery system (ductwork), and a heat exchanger-a system of pipes buried in the shallow ground near the building

-in the winter, the heat pump removes heat from the heat exchanger and pumps it into the indoor air delivery system

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-the heat removed from the indoor air during the summer can also be used to provide a free source of hot water