Question

7a & b, 9

= 7.85 h z Population Growth The population of a southern city follows the exponential law. If N is the population of the city and t is the time in vears, express N as a function of t. N(t) = Nock (b) If the population doubled in size over an 18-month period and the current population is 10,000, what will the population be 2 years from now? 25,198 & Population Decline The population of a midwestern city (a) If N is the population of the city and t is the time in follows the exponential law. C 16. V te te tH st ta P 17. D CO in un wa years, express N as a function of t. N(t) = Noekt, k < 0 (b) If the population decreased from 900,000 to 800,000 from 2005 to 2007, what was the population in 711,111 9. Radioactive Decay The half-life of radium is 1690 years. If 10 grams is present now, how much will be present in 50 years? 9.7979 2009? pe: the be 72 mu

Answer 1

Solution' @lit 'Ho is of city and let K = population of growth or decay Rate. time "t? with so N ap function of t Kt N(+)= No.e > y let ur be. The growth Rate [ro] 18 : () 2) 18= 1-03926 per month Initial population : 10,000 t=q yar 24 monthy

10,000 [ 1.03926] 24 =) 25,198 population After a yeary After a years = 25, 198 1690 9 0.5 (1/1690) r (0.5) く一 750.999589 50. N(+) - No. (0.99959) NCH) = 10 [ 0.99959350 AN(A) = 9.797 g my The end <