Model 2 The rabbit population grows exponentially according to the rule: R = 400 390 x 1.01n – Find the population after 10 years, 20 years, 30 years, 40 years and 50 years. by using a calculator and substituting the values in. How many years does it take for there to be a million rabbits in the fields? What happens in this model? By plotting the graph of R against n in multiples of 10 what can you say happens to the population in the long term? Activity D The half-life of a radioactive substance is the time taken for a given amount of the substance to become reduced by half because of radioactive decay. There are two definitions of half-life, but they mean the same in practice. Half-life is the time taken for: The number of atoms in a sample to halve because of radioactive decay The Geiger counter count rate from a sample to fall to half its starting level. The half live of the radioactive element Caesium-134 is 2 hours, so that starting with a Geiger counter reading of 64 clicks a second for a sample of Caesium-134. 2 hours later it will be 32 clicks per second 4 hours after the start it will be 16 clicks per second 8 hours after the start it will be 8 clicks per second And so on … Use the information above to calculate how many clicks for these times after starting. 32 hours
Model 2 The rabbit population grows exponentially according to the rule: R = 400 – 390 x 1.01n Find the population after 10 years, 20 years, 30 years, 40 years and 50 years. by using a calculator and substituting the values in. How many years does it take for there to be a million rabbits in the fields? What happens in this model? By plotting the graph of R against n in multiples of 10 what can you say happens to the population in the long term? Activity D The half-life of a radioactive substance is the time taken for a given amount of the substance to become reduced by half because of radioactive decay. There are two definitions of half-life, but they mean the same in practice. Half-life is the time taken for: The number of atoms in a sample to halve because of radioactive decay The Geiger counter count rate from a sample to fall to half its starting level. The half live of the radioactive element Caesium-134 is 2 hours, so that starting with a Geiger counter reading of 64 clicks a second for a sample of Caesium-134. 2 hours later it will be 32 clicks per second 4 hours after the start it will be 16 clicks per second 8 hours after the start it will be 8 clicks per second And so on … Use the information above to calculate how many clicks for these times after starting. 32 hours
281294-exponential-growth-and-decay-learner-activity.docx