1. Not finding help here? Sign up for a free 30min 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!

Two-dimensional motion

  1. Jul 12, 2007 #1
    Motion in one dimension means that something always runs in a straight line? So how about two-dimensional motion? What does that mean literally?For instance, Why projectile is a two-dimensional motion? It's a parabolic path? so what does 'two-dimensional' mean here? thanks.
  2. jcsd
  3. Jul 12, 2007 #2


    User Avatar

    It means that there is a level plane, for which if the path were projected onto it, the path would remain unchanged.
    Last edited: Jul 12, 2007
  4. Jul 12, 2007 #3
    ok, here is a question: A hummingbird, 3.4m above the ground, flies 1.2m along a straight path. Upon spotting a flower below, the hummingbird drops directly downward 1.4m to hover in front of the flower. What is the hummingbird's total displacement? I can't imagine a pic in my head.
    Humming bird-------- (1.2m) flies
    / (3.4m)
    -------- (ground) but where is the flower?
  5. Jul 12, 2007 #4

    Chi Meson

    User Avatar
    Science Advisor
    Homework Helper

    2 dimensional motion refers to motion that can be depicted on a simple graph with x and y coordinates. A parabola, as you follow it's path, changes both its x position and its y position. A projectile follows a parabolic path, and as it moves, it changes its horizontal (x) and vertical (y) positions simultaneously.

    If you threw a curve ball, then it would also move sideways, as it moved forward and down, but that's getting too complicated too quickly.

    In the hummingbird question, this is not a projectile problem. The hummingbird moves a horizontal distance, then a vertical distance. Draw a straight line horizontally, then at the end of that line, draw one downward. This is the path of the bird.

    Now find the displacement, which is the straight line between the starting point and the ending point. Do you see a triangle?
  6. Jul 12, 2007 #5
    yes, OHH, i thought the flies is a noun, not a verb which means 'fly'. ok, thank you.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: Two-dimensional motion
  1. Two Dimensional Motion (Replies: 5)

  2. Two dimensional motion (Replies: 8)