
Math General Math Forum  For general math related discussion and news 
 LinkBack  Thread Tools  Display Modes 
January 17th, 2017, 04:10 PM  #1 
Newbie Joined: Jan 2017 From: Warrington Posts: 2 Thanks: 0  Exponential Decay
The equation for exponential decay is N = N0 e^(at) where N is the population at time t and N0 the amount at time t = 0. Find the age t , if an initial population of 14C atoms has decayed to 0.1% of its original amount and the decay parameter a is 1.226 × 104 y1. Any suggestions/agreement on the answer to this question. Please note that the 'a' is supposed to be an alpha symbol, although an 'a' does the same job. I have an answer of 56344 years, although I'm doubting this answer as this just about on the borderline of the maximum age for carbon dating. Thanks in advance. 
January 17th, 2017, 04:23 PM  #2 
Math Team Joined: Jul 2011 From: Texas Posts: 2,767 Thanks: 1422 
works fine for me ... if they really detected a 0.1% carbon 14 level $N = N_0 e^{at}$ 100% of $C_{14}$ at $t = 0$ $0.1 = 100 e^{at}$ $0.001 = e^{at}$ $\ln(0.001) = at$ $t = \dfrac{\ln(0.001)}{a} = \dfrac{\ln(0.001)}{1.226 \times 10^{4}} = 56344$ years 

Tags 
decay, exponential, math 
Thread Tools  
Display Modes  

Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Exponential Growth and Decay Help  swm06  Algebra  2  April 6th, 2013 03:22 PM 
Logarithm and exponential decay  lechatelier  Algebra  5  June 4th, 2012 10:37 PM 
Exponential Growth and Decay  MathsBeforeBedtime  Algebra  2  May 21st, 2011 06:36 AM 
exponential decay problem  the_liong  Calculus  1  October 17th, 2009 05:03 AM 
Exponential Growth and Decay  symmetry  Algebra  1  April 22nd, 2007 06:20 AM 