Pre-Calculus Practice Problem 110

Pre-Calculus Practice Problem 110 - 3. A radioactive...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
Unit 3, Activity 8, Applications Involving Exponential Growth and Decay Blackline Masters, Advanced Math-Pre-Calculus Page 108 Comprehensive Curriculum, Revised 2008 1. The number of radioactive atoms N of a particular material present at time t years may be written in the form N = 5000e - kt , where 5000 is the number of atoms present when t = 0, and k is a positive constant. It is found that N = 2500 when t = 5 years. a) Determine the value of k. b) At what value of t will N = 50? 2. A cup of coffee contains about 100 mg of caffeine. The half-life of caffeine in the body is about 4 hours, which means that the level of caffeine in the body is decaying at the rate of about 16% per hour. a) Write a formula for the level of caffeine in the body as a function of the number of hours since the coffee was drunk. b) How long will it take until the level of caffeine reaches 20 mg?
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 3. A radioactive substance has a half-life of 8 years. If 200 grams are present initially, a) How much will remain at the end of 12 years? b) How long will it be until only 10% of the original amount remains? 4. The Angus Company has a manufacturing process that produces a radioactive waste byproduct with a half-life of twenty years. a) How long must the waste be stored safely to allow it to decay to one-quarter of its original mass? b) How long will it take to decay to10% of its original mass? c) How long will it take to decay to 1% of its original mass? 5. A bacteria population triples every 5 days. The population is P o bacteria. a) Write an equation that reflects this statement. b) If the initial population is 120, what is the population i) after 5 days? ii) after 2 weeks?...
View Full Document

This note was uploaded on 10/10/2011 for the course MAC 1147 taught by Professor German during the Fall '08 term at University of Florida.

Ask a homework question - tutors are online