Results 1 to 5 of 5

Math Help - velocity and speed

  1. #1
    Member jacs's Avatar
    Joined
    Jan 2006
    From
    Sydney
    Posts
    107

    velocity and speed

    Equation is: x = 12t - t.
    Calculate the average velocity and the average speed.

    So far I have this.
    v = 12 - 2t

    Can the answer be determined from just this info? Or is smt missing? (My teacher is fond of making errors in questions....grrrr)

    thanks
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor Quick's Avatar
    Joined
    May 2006
    From
    New England
    Posts
    1,024
    Quote Originally Posted by jacs
    Equation is: x = 12t - t.
    Calculate the average velocity and the average speed.

    So far I have this.
    v = 12 - 2t

    Can the answer be determined from just this info? Or is smt missing? (My teacher is fond of making errors in questions....grrrr)

    thanks
    What is your equation above supposed to represent?

    the area in red isn't right becuase  x-x^2 can't be simplified.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Member jacs's Avatar
    Joined
    Jan 2006
    From
    Sydney
    Posts
    107
    x is the equation of rectilinear motion, displacement x, in terms of t, time

    usually we use this kind of thing to find instantaneous velocity or acceleration. I have not seen a question before on average speed or velocity without a specific time given.
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Forum Admin topsquark's Avatar
    Joined
    Jan 2006
    From
    Wellsville, NY
    Posts
    9,853
    Thanks
    321
    Awards
    1
    Quote Originally Posted by jacs
    Equation is: x = 12t - t.
    Calculate the average velocity and the average speed.

    So far I have this.
    v = 12 - 2t

    Can the answer be determined from just this info? Or is smt missing? (My teacher is fond of making errors in questions....grrrr)

    thanks
    v = 12 - 2t is the instantaneous velocity.

    Given a specific time interval:

    Average velocity = \frac{1}{t-t_0} \int_{t_0}^t \, dt (12 - 2t)

    Average speed = \frac{1}{t-t_0} \int_{t_0}^t \, dt |12 - 2t|

    -Dan
    Last edited by topsquark; June 24th 2006 at 05:38 AM. Reason: AARGH! I made a boo boo!
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Member jacs's Avatar
    Joined
    Jan 2006
    From
    Sydney
    Posts
    107
    thanks Dan, i understand the general expression, it makes sense, cheers.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. [SOLVED] Finding the speed from the velocity
    Posted in the Advanced Applied Math Forum
    Replies: 3
    Last Post: February 8th 2009, 09:56 AM
  2. acceleration - velocity & speed
    Posted in the Calculus Forum
    Replies: 7
    Last Post: November 12th 2008, 01:48 PM
  3. [SOLVED] speed & velocity
    Posted in the Advanced Applied Math Forum
    Replies: 1
    Last Post: February 27th 2008, 12:13 PM
  4. speed velocity
    Posted in the Math Topics Forum
    Replies: 3
    Last Post: February 23rd 2007, 08:35 AM
  5. speed and velocity
    Posted in the Pre-Calculus Forum
    Replies: 2
    Last Post: October 9th 2006, 04:54 AM

Search Tags


/mathhelpforum @mathhelpforum