Exponential Growth and Decay 10.6

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Exponential Growth and Decay10.6
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Exponential Growth and Decay

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Example 6-1a
Ex 1
A cup of coffee contains 130 milligrams of
caffeine. If caffeine is eliminated from the body
at a rate of 11 per hour, how long will it take
for 90 of this caffeine to be eliminated from a
persons body?
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Example 6-1a
Ex 2
An adult dose of aspirin is 650 milligrams. If
aspririn is eliminated from the body at a rate of
15 per hour, how long will it take for 80 of
this dose to be eliminated from a persons body?
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Example 6-1a
Ex 3
The half-life of Sodium-22 is 2.6 years.What is
the value of k for Sodium-22?
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Example 6-1a
Ex 4
A geologist examining a meteorite estimates that
it contains only about 10 as much Sodium-22 as
it would have contained when it reached the
surface of the Earth. How long ago did the
meteorite reach the surface of the Earth?
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Example 6-1a
Ex 5
The half-life of radioactive iodine used in
medical studies is 8 hours. a. What is the value
of k for radioactive iodine? b. A doctor wants
to know when the amount of radioactive
iodine in a patients body is 20 of the
original amount. When will this occur?
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Example 6-1a
Ex 6
The population of a city of one million is
increasing at a rate of 3 per year. If the
population continues to grow at this rate, in how
many years will the population have doubled?
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Example 6-1a
Ex 7
The population of a city of 10,000 is increasing
at a rate of 5 per year. If the population
continues to grow at this rate, in how many years
will the population have doubled?