1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Latitude Longitude -> Polar Form -> Cartesian Coordinates

  1. Feb 28, 2008 #1
    [SOLVED] Latitude Longitude -> Polar Form -> Cartesian Coordinates

    1. The problem statement, all variables and given/known data

    I need to convert 46 Degrees North 80 Degrees west into Cartesian coordinates, based on the assumption that the earth is a sphere (althought it's not).

    2. Relevant equations


    3. The attempt at a solution

    I've attempted to convert and I got ( -767.18, -4350.91, 4575 )
    Not sure if this is correct. I'd like to know the North and West signs factor into the equation when plugging in. Can anyone help, or show me a step by step basis please??
  2. jcsd
  3. Feb 28, 2008 #2


    User Avatar
    Science Advisor

    HOW have you set up your cartesian coordinate system? I assume the origin is at the center of the earth and the positive z-axis runs through the north pole. Is the positive x-axis pointing toward the Greenwich meridion (i.e. longitude= [itex]\theta[/itex]= 0)? And be sure you handle [itex]\phi[/itex] correctly. In spherical coordinates [itex]\phi[/itex] is the "co-latitude": measured from the north pole rather than from the equator.

    If so, then 80 degrees West longitude means that x will be positive (beyond 90 degrees W longitude would make x negative) but that y will be negative (any west longitude makes y negative). Since latitude is north, z will be positive but be sure to use [itex]\phi[/itex]= 90- 46= 44 degrees.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook