Results 1 to 2 of 2

Math Help - Study guide problem Half-lifes!

  1. #1
    Junior Member
    Joined
    Oct 2007
    Posts
    30

    Lightbulb Study guide problem Half-lifes!

    4. The half-life of lead-209 is 3.3 hours. The initial amount S grams.

    a. Express the amoundt of substance S remaining as a function of time t.
    b. How mmuch of the substance is left after 3.3 hourse? after 33 hours?
    c. Determine S if there is 5 g left after 22 hours.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Flow Master
    mr fantastic's Avatar
    Joined
    Dec 2007
    From
    Zeitgeist
    Posts
    16,948
    Thanks
    5
    Quote Originally Posted by rlarach View Post
    4. The half-life of lead-209 is 3.3 hours. The initial amount S grams.

    a. Express the amoundt of substance S remaining as a function of time t.
    b. How mmuch of the substance is left after 3.3 hourse? after 33 hours?
    c. Determine S if there is 5 g left after 22 hours.
    a. Standard formula: m = m_0 \left( \frac{1}{2} \right)^{\frac{t}{t_{1/2}}}

    where t_{1/2} is the half-life (in hours) and m_0 is the initial amount (in gram).

    So the answer to a. is ........

    b. Sub t = 3.3 and solve for m. Alternatively, note that t = 1 half-life .....
    Sub t = 33 and solve for m.

    c. Sub m = 5 and t = 22 and solve for S.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Study Guide for Actuarial Exams?
    Posted in the Business Math Forum
    Replies: 8
    Last Post: June 15th 2011, 07:50 PM
  2. Help on Study Guide
    Posted in the Discrete Math Forum
    Replies: 1
    Last Post: June 11th 2011, 11:13 AM
  3. Need help on study guide
    Posted in the Algebra Forum
    Replies: 2
    Last Post: May 3rd 2011, 10:30 AM
  4. Exam study guide help
    Posted in the Advanced Algebra Forum
    Replies: 2
    Last Post: December 15th 2009, 10:59 PM
  5. Study Guide Help
    Posted in the Advanced Statistics Forum
    Replies: 0
    Last Post: December 5th 2008, 10:59 PM

Search Tags


/mathhelpforum @mathhelpforum