Please help

Question

Australia has a uranium resource equivalent to 700,000 petajoules (PJ). If this resource was divided equally amoung the worlds population of 7 billion people over a 1000-year period, what would be the average energy per-person per-day?

Answer 1

Valerie,

 

You have a few conversions involved so you have to know what a peta means (=1000 Trillion = 10¹⁵ in scientific notation), a billion people is 10⁹, and a year has 365.25 days over a long span to account for leap years.  Then:

 

Energy per person per day = (Available uranium energy)/(population of the earth)/(number of days in 1000 years)

                                       = (7 x 10⁵ x 10¹⁵ joules) / (7 x 10⁹ people) / (365.25 x 10³ days)

                                       = (7 x 10²⁰ joules) / (7 x 10⁹ people) / (3.6525 x 10⁵ days)

                                       = ( 1.0 x 10¹¹ joules per person)  / (3.6525 x 10⁵ days)

                                       = 2.738 x 10⁵  

                                       = 273,800 joules per person per day