Results 1 to 3 of 3

Thread: Time of death problem involving a constant variable, K

  1. #1

    Time of death problem involving a constant variable, K

    Coroners estimate time of death using the rule of thumb that a body cools about 2 degrees F during the first hour after death and about 1 degree F for each additional hour. Assuming an air temperature of 72 degrees F and a living body temperature of 98.6 degrees F, the temperature T(t) in degrees F of a body at a time t hours since death is given by
    T(t) = 72 + 26.6 e^{-kt}.

    For what value of k will the body cool by 2 degrees F in the first hour?

    I think that the k is throwing me off a bit because I tried plugging in the values and isolating the k but none of my answers are correct. Can someone help please?

  2. #2
    Junior Member Unknown008's Avatar
    Join Date
    Sep 2011
    Location
    Mauritius
    Posts
    148
    Quote Originally Posted by kinz.kb View Post
    Coroners estimate time of death using the rule of thumb that a body cools about 2 degrees F during the first hour after death and about 1 degree F for each additional hour. Assuming an air temperature of 72 degrees F and a living body temperature of 98.6 degrees F, the temperature T(t) in degrees F of a body at a time t hours since death is given by
    T(t) = 72 + 26.6 e^{-kt}.

    For what value of k will the body cool by 2 degrees F in the first hour?

    I think that the k is throwing me off a bit because I tried plugging in the values and isolating the k but none of my answers are correct. Can someone help please?
    T(t) is T(1) and is hence 98.6 - 2 (This is the temperature of the body after 1 hour)

    t = 1

    So, your equation becomes:

    [tex]96.6 = 72 + 26.6 e^{-k(1)}[/tex]

    Is that okay? =]

  3. #3
    Elite Member mmm4444bot's Avatar
    Join Date
    Oct 2005
    Location
    Seattle
    Posts
    9,347
    Quote Originally Posted by kinz.kb View Post

    I tried plugging in the values and isolating the k but none of my answers are correct.

    Maybe you made an arithmetic mistake somewhere?

    Can someone help please?

    If you were to show us what you tried, we could show you what went wrong.
    .

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •