Students are collecting data as they control the toy helicopter shown. The helicopter has a mass m and must exert a thrust of power P0 to initially move upward with a constant speed v0 . The students then cause the helicopter to exert a thrust so that a net force Fnet=2mg accelerates it upward. As the helicopter is accelerating, it has a thruster power Pf , and as it passes a height h0 it has a speed of 3v0 . The ratio PfP0 is most nearly

t.                 w               e                 n                   t                 y                 c             h               a           r           a               c                 t             e             r             s        

the answer is a. the yacht traveled from the dock north to the 200-meter marker in the bay in less than 5 minutes, giving the passengers several more hours to fish.

im doing peak rn so sry if its wrong

-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

compass can be used day and night, cloudy or sunny