Results 1 to 6 of 6

Math Help - To find a solution to this Differential Equation?

  1. #1
    Junior Member
    Joined
    Nov 2009
    Posts
    60

    To find a solution to this Differential Equation?

    For the equation:

    dv/dt=-kx^{1/2}

    I do not seem to be able to solve this one to find the general solution! :S
    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
    Are you sure that is the equation?

    could it be \frac{dv}{dt}=-kt^{1/2}

    or

    \frac{dv}{dt}=-kv^{1/2} ?
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Junior Member
    Joined
    Nov 2009
    Posts
    60
    Quote Originally Posted by pickslides View Post
    Are you sure that is the equation?

    could it be \frac{dv}{dt}=-kt^{1/2}

    or

    \frac{dv}{dt}=-kv^{1/2} ?

    YES sorry my bad! It is the second one! Can you help?
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Master Of Puppets
    pickslides's Avatar
    Joined
    Sep 2008
    From
    Melbourne
    Posts
    5,236
    Thanks
    28
    Happy to kick it off for you

    \frac{dv}{dt}=-kv^{1/2}

    separating the variables you get

    \frac{dv}{v^{1/2}}=-k~dt

    Now integrate both sides

    Hint: \int \frac{dv}{v^{1/2}} = 2v^{1/2}
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Junior Member
    Joined
    Nov 2009
    Posts
    60
    Quote Originally Posted by pickslides View Post
    Happy to kick it off for you

    \frac{dv}{dt}=-kv^{1/2}

    separating the variables you get

    \frac{dv}{v^{1/2}}=-k~dt

    Now integrate both sides

    Hint: \int \frac{dv}{v^{1/2}} = 2v^{1/2}
    Right, so therefore the general solution is:

    v=4(-kt+c)^{1/2}


    am i right?
    Follow Math Help Forum on Facebook and Google+

  6. #6
    Master Of Puppets
    pickslides's Avatar
    Joined
    Sep 2008
    From
    Melbourne
    Posts
    5,236
    Thanks
    28
    How did you get that?

    I get v = \left( \frac{-kt+C}{2}\right)^2
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 8
    Last Post: April 20th 2011, 12:03 AM
  2. Find the general solution of the differential equation specified..
    Posted in the Differential Equations Forum
    Replies: 2
    Last Post: March 14th 2011, 03:39 AM
  3. Find the particular solution of the differential equation
    Posted in the Differential Equations Forum
    Replies: 1
    Last Post: November 15th 2010, 02:29 AM
  4. Find a differential equation given solution
    Posted in the Differential Equations Forum
    Replies: 1
    Last Post: September 21st 2010, 12:15 AM
  5. Find the second solution of a differential equation
    Posted in the Differential Equations Forum
    Replies: 1
    Last Post: June 24th 2008, 09:10 AM

Search Tags


/mathhelpforum @mathhelpforum