This preview shows pages 1–2. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: Math 135 Supplement for WebWork HW03 Fall 2010 Prepared by Kellen Myers Several students have inquired about problem 26 from the WebWork. It reads: A bacteria culture initially contains 2500 bacteria and doubles every half hour. With t representing minutes, the formula for the population is p ( t ) = 2500 e kt for some constant k . 1. k = 2. The size of the bacterial population after 60 minutes is . 3. The size of the bacterial population after 9 hours is . Note that the constants (2500, 60, 9) vary from question to question. The general roadblock students come across is this: Compute k by solving: p (30) = 5000 2500 e 30 k = 5000 e 30 k = 2 30 k = ln(2) k = ln(2) / 30 WebWork will accept either ln(2)/30 or an approximation like 0.231. This is where things start to go wrong. The next thing the student does is enter the k and t values to compute the second part of this question: p (60) = 2500 e . 231 60 This can be plugged right into a calculator to achieve the approximation 9997.05.This can be plugged right into a calculator to achieve the approximation 9997....
View
Full
Document
This document was uploaded on 11/02/2011 for the course MATH 135 at Rutgers.
 Fall '08
 NOONE
 Math, Calculus

Click to edit the document details