physics assignment

1. A bird species in danger of extinction has a population that is decreasing exponentially (A = A0e^kt). Five years ago, the population was at 1400 and today only 1000 of the birds are alive. Once the population drops below 100, he situation will be irreversible. When will this happen?
   
   
2. According to the U. S. Bureau of the Census, in 2000 there were 35.3 million residents of Hispanic origin living in the United States. By 2010, the number had increased to 50.5 million. The exponential growth function A = 35.3e^kt describes the U.S. Hispanic population, A, in millions, t years after 2000.

a. Find k, correct to three decimals places.

b. Use the resulting model to project the Hispanic resident in population in 2015.

c. In which year will the Hispanic resident population reach 70 million?