N 2000, a 20-year-old astronaut left Earth to explore the galaxy; her spaceship travels at 2.5 x 10^8 m/s. She returns in 2040. About how old will she appear to be?

she'll be 42.3 years old

Explanation:

The year she left is 2020

she returns in 2040

the time observed to have passed by on earth is 40 years

she traveled at a speed of 2.5 x 10^8 m/s

From relativity, the astronaut will experience a time dilation and will age more slowly.

the time that is observed to pass on her ship will be gotten from

t' =

where t is the time that is observed to pass by an earthly observer

v is the speed of her ship

c is the speed of light = 3 x 10^8 m/s

v/c = 2.5/3 = 0.83  

t' = = 40 x 0.5578 = 22.3 years would have passed for her

This means that she'll be 20 + 22.3 = 42.3 years old

-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

im srry but ur wrong the answer is d a smooth rock, some red dirt, and an empty bird's nest.