1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Simple log problem

  1. Dec 23, 2005 #1
    If 3150g of a radioactive substance decays to 450g in 73 weeks, determine the half life of the substance to the nearest week. Solve algebraically using logarithms.

    450=3150(x)^73
    450/3150=x^73
    73sqrt(450/3150)=x

    Now, the only problem is the answer says it is 26 weeks. Any help is much appreciated.
     
  2. jcsd
  3. Dec 23, 2005 #2

    Tide

    User Avatar
    Science Advisor
    Homework Helper

    You're starting with the wrong equation. Try something like

    [tex]450 = 3150 \left( \frac {1}{2} \right)^{73/T}[/tex]

    where T is the half-life.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook