Results 1 to 2 of 2

Math Help - Urgent help on related rates:

  1. #1
    Senior Member
    Joined
    Jul 2006
    From
    Shabu City
    Posts
    381

    Urgent help on related rates:

    An airplane flies at a height of 9km in the direction of an observer on the ground at a speed of 800kph. Find the rate of change of the angle of elevation of the plane from the observer at the instant when the angle is \pi over 4 radians.
    Ill be the one to differentiate this:
    Last edited by ^_^Engineer_Adam^_^; March 18th 2007 at 07:36 AM.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Grand Panjandrum
    Joined
    Nov 2005
    From
    someplace
    Posts
    14,972
    Thanks
    4
    Quote Originally Posted by ^_^Engineer_Adam^_^ View Post
    An airplane flies at a height of 9km in the direction of an observer on the ground at a speed of 800kph. Find the rate of change of the angle of elevation of the plane from the observer at the instant when the angle is \pi over 4 radians.
    Ill be the one to differentiate this:
    Assume a flat Earth, then the angle of elevation phi satisfies:

    tan(phi) = height/range ... (1)

    height = 9000 m.

    d range/dt = 800000*60*60 m/s.

    When the elevation is pi/4 rad, the range is 9000 m.

    Use implicit differentiation on (1), and plug in what you know to find d phi/dt.

    RonL
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Need urgent help with Related Rates
    Posted in the Calculus Forum
    Replies: 4
    Last Post: July 22nd 2009, 10:45 AM
  2. Rates and Related Rates!!
    Posted in the Calculus Forum
    Replies: 1
    Last Post: April 2nd 2008, 10:53 AM
  3. Related Rates, urgent
    Posted in the Calculus Forum
    Replies: 2
    Last Post: February 27th 2007, 07:43 AM
  4. Related rates: urgent
    Posted in the Calculus Forum
    Replies: 1
    Last Post: January 6th 2007, 09:25 PM
  5. Related rates: urgent
    Posted in the Calculus Forum
    Replies: 2
    Last Post: January 6th 2007, 05:00 PM

Search Tags


/mathhelpforum @mathhelpforum