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How far must the quarterback throw the ball?

  1. Sep 8, 2011 #1
    1. The problem statement, all variables and given/known data

    At Enormous State University (ESU), the football team records its plays using vector displacements, with the origin taken to be the position of the ball before the play starts. In a certain pass play, the receiver starts at +2.0 {i} - 5.0 {j}, where the units are yards, {i} is to the right, and {j} is downfield. Subsequent displacements of the receiver are +9.0 {i}(in motion before the snap), +10 {j}(breaks downfield), - 6.0{i}+ 4.0 {j}(zigs), and +12.0{i} + 18.0 {j} (zags). Meanwhile, the quarterback has dropped straight back to a position - 7.0 {j}.


    How far must the quarterback throw the ball?


    In which direction must the quarterback throw the ball?


    2. Relevant equations

    Probably Rx+Ry=R


    3. The attempt at a solution

    I drew the diagram.

    Do I have to use two triangles to figure this out, then add those vectors, or something? I would find the components but I don't have any angles to work with(that I know of).

    Did you guys have the receiver end on coords (17,27) and the QB on coords(0,-7)?

    (17)^2+(34)^2, then square root = 38.0 yards
    tan-1 (34/17) = 90-63.43 = 26.5 degrees to right of downfield.

    Is that right for yards. Doesn't seem right.
    Thanks!
     
    Last edited: Sep 8, 2011
  2. jcsd
  3. Sep 8, 2011 #2
    Re: Vectors

    What's the question?
     
  4. Sep 8, 2011 #3
    Re: Vectors

    How far must the quarterback throw the ball?


    In which direction must the quarterback throw the ball?
     
  5. Sep 8, 2011 #4
    Re: Vectors

    Alright, I figure out this is correct.
     
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