An automobile engine is 15 percent efficient. how many joules of input work are required to produce 15,000 joules of output work to move the car?

100,000Joules

Explanation:

Efficiency of machines is the ratio of work done by machine (work output) to the work put in the machine (work input)

Efficiency = Work output/Work input

Given efficiency = 15%

Work output = 15,000Joules

Work Input = ?

Substituting in the formula of efficiency

15% = 15,000/Work Input

15/100 = 15,000/Work Input

15× Work input = 15,000×100

15 × Work input = 1,500,000

Work input = 1,500,000/15

Work input = 100,000Joules

-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

the total distance that martina travels that day is

(distance from home to mom's office) plus (distance from mom's office to school)

plus (distance from school to library) plus (distance from library to friend's house)

plus (distance from friend's house to martina's house).

(we don't know what any of these distance actually is.)