In February 2002, a total of 60.7 billion kW · h of electrical energy was genera
ID: 1444284 • Letter: I
Question
In February 2002, a total of 60.7 billion kW · h of electrical energy was generated by nuclear power plants in the United States. At that time, the population of the United States was about 287 million people. If the average American has a mass of 60 kg, and if 16.73% of the entire energy output of all nuclear power plants was diverted to supplying energy for a single giant elevator, estimate the height h to which the entire population of the country could be lifted by the elevator. In your calculations, assume also that g is constant over the entire height h. Find height in meters.
Explanation / Answer
E = energy = 60.7 x 109 KWh
1 KWh = 3.6 x 106 J
so E = (60.7 x 109 ) (3.6 x 106 ) = 2.185 x 1017 J
m = mass = 60 kg
n = number of persons = 287 x 106
h = height gained
PE gained = 0.1673 E
n mgh = 0.1673 E
(287 x 106) (60) (9.8) h = 0.1673 (2.185 x 1017)
h = 216615 m