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Homework Help: Projectile motion

  1. May 1, 2009 #1


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    1. The problem statement, all variables and given/known data
    A projectile is fired from the edige of a building with initial velocity of v0=10 m/s at an angle of 45 degrees. The rojectile rises and then lands oln ground at point P as shown, which is 35.4 meters away from the base of building. A) Find the Y component of the projectile's position at t =2.4 seconds and the maximum height the projectile reaches. Drawing is attached too..

    2. Relevant equations
    Vsina0 + -1/2gt^2

    3. The attempt at a solution
    Used the given equation for both parts but got them wrong..

    Attached Files:

    • mg.jpg
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  2. jcsd
  3. May 1, 2009 #2


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    Homework Helper

    You know vertical velocity initially.

    10 * .707 = 7.07 m/s

    But your equation is wrong.

    Y = h + Vy*t - 1/2*g*t2

    You need to figure h the height of the building.

    You can determine that from the x-distance at impact

    35.4/Vx = 35.5 / 7.07 = total time

    Since at total time that tells you where the object reaches 0 in the equation, that should tell you h. With h, you can figure Y at 2.4 sec.

    Figure the time to max height and that gives you the Y of max height, all from the same equation for Y.
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