The units we use to measure the sound intensity level are .

decibels (dB)

Explanation:

The sound intensity level is a quantity derived from the sound intensity.

The intensity of a wave is defined as the power of the source of the wave divided by the area through which the power of the wave is spread, mathematically:

where

P is the power of the source

is the surface area over which the wave spreads (assuming that the wave propagates in all directions, it corresponds to the surface area of a sphere of radius , where r is the distance between the source of the wave and the observer)

For sound waves, the intensity is often expressed using another unit, called decibel (dB), defined as follows:

where

is the sound intensity level in decibels

I is the intensity of the sound wave

is the threshold intensity of a sound that a person can normally hear.

from

explanation:

wind is defined by the direction it blows from.   for example, a wind blowing from north to south is called a northerly wind.

-first use of geothermal energy occurred more than 10,000 years ago in north america by american paleo-indians

-the first industrial use of geothermal energy began near pisa, italy in late 18th century

-in 1904, italian scientist piero ginori conti invented the first geothermal electric power plant in which steam was used to generate the power

-with the above experiment, the first geothermal plant in usa started in 1922 with a capacity of 250 kilowatts

-however, in 1946 first ground-source geothermal heat pump installed at commonwealth building in portland, oregon

-during the 1960’s, pacific gas and electric began operation of first large scale geothermal power plant in san francisco, producing 11 megawatts

-in 1973, when oil crisis began many countries began looking for renewable energy sources and by 1980’s geothermal heat pumps (ghp) started gaining popularity in order to reduce heating and cooling costs

-as effect of climate change started showing results, governments of various countries joined hands to fight against it, for which kyoto protocol was signed in japan in 1997, laid out emission targets for rich countries and required that they transfer funds and technology to developing countries, 184 countries have ratified it

hope this