Results 1 to 4 of 4

Math Help - Math Test Question

  1. #1
    Newbie
    Joined
    Nov 2009
    Posts
    12

    Math Test Question

    A Lab has a 500g sample of nitrogen. The substance has a half life of about 10 minutes.

    Write a formula to express this.... I think I got this answer

    V=500(250)^10

    How much nitrogen is left after 30 min?

    How much is left after an hour?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Master Of Puppets
    pickslides's Avatar
    Joined
    Sep 2008
    From
    Melbourne
    Posts
    5,236
    Thanks
    28
    Quote Originally Posted by Cdawson View Post

    V=500(250)^10
    Where did the 250 come from?
    Follow Math Help Forum on Facebook and Google+

  3. #3
    MHF Contributor
    Joined
    Dec 2007
    From
    Ottawa, Canada
    Posts
    3,102
    Thanks
    68
    250^10 = 953,674,316,406,250,000,000,000
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Junior Member
    Joined
    Nov 2009
    Posts
    63
    Quote Originally Posted by Cdawson View Post
    A Lab has a 500g sample of nitrogen. The substance has a half life of about 10 minutes.

    Write a formula to express this.... I think I got this answer

    V=500(250)^10

    How much nitrogen is left after 30 min?

    How much is left after an hour?
    the general equation for decay problem:
    V=A(r)^n
    A= sample start
    r = rate of decay
    n = period

    in this case,
    V=A(r)^n
    A= 500
    r = 0.5
    n = 1 (1 = 10 minute)
    V=500 (0.5)^1

    how many after 30 minutes??
    V=A(r)^n
    A= 500
    r = 0.5
    n = 3 (1 = 10 minute)
    V=500 (0.5)^3

    how many after 1 hour???
    (hint: you just convert hour to minute it would be the n)

    ....hope it help....
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. [SOLVED] Can Someone Answer This Math Test Question?
    Posted in the Geometry Forum
    Replies: 2
    Last Post: March 20th 2011, 06:22 PM
  2. Math Test Help
    Posted in the Algebra Forum
    Replies: 4
    Last Post: February 14th 2010, 06:08 PM
  3. I need help with this math test!
    Posted in the Algebra Forum
    Replies: 1
    Last Post: September 21st 2009, 11:20 AM
  4. Math test help
    Posted in the Pre-Calculus Forum
    Replies: 1
    Last Post: November 29th 2008, 08:20 AM
  5. Math help, test tommorow.
    Posted in the Algebra Forum
    Replies: 3
    Last Post: October 19th 2006, 08:27 PM

Search Tags


/mathhelpforum @mathhelpforum