Have you ever wondered how much of the energy you use comes from wind power?
can the growth of the number of wind farms in the united states be modeled by a linear function? can you determine how much wind power will be needed in the future?

1. in 2012, the united states generated approximately 3.5% of its electricity from wind power. approximately 4 trillion kilowatt hours (kwh) of electricity was used.
a. a terawatt hour (twh) is equal to 1,000,000,000 kilowatt hours. how many terawatt hours is equal to 4 trillion kilowatt hours?

b. how much of the electricity in 2012 came from wind power? write your answer in terawatt hours.

c. you will be writing an equation which represents wind farm growth since 2012. what ordered pair can you use as your initial value?

2. one goal for the united states is to be able to generate 20% of its electricity by the year 2030 using wind power. if the country used the same amount of electricity in 2030 as it did in 2012, how much of the electricity (in terawatt hours) would be generated by wind power? what ordered pair can you use to represent this value?

3. using the two data points from exercises 1 and 2, write a linear equation that shows how the wind power would need to grow to make this goal. use years for the independent variable and terawatt hours for the dependent variable. let year 0 represent year 2012.
a. write your equation in slope-intercept form.

b. explain what the slope and y-intercept represent in this situation.

c. insert a graph of your line.