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Homework Help: Projectile motion

  1. Sep 20, 2010 #1
    1. The problem statement, all variables and given/known data
    A firefighter, 44.0 m away from a burning building, directs a stream of water from a ground level fire hose at an angle of 31.2° above the horizontal. If the speed of the stream as it leaves the hose is 40.0 m/s, at what height will the stream of water strike the building?
    v=40.0m/s
    v(x)=vcos31.2
    v(y)=vsin31.2
    g=9.81
    2. Relevant equations
    R=(vsin^2(31.2))/g
    x(t)=vcos(31.2)


    3. The attempt at a solution
    I have tried breaking it down to x and y components but it doesn't make sense if the height of the building and its distance from the firefighter is not given !
     
  2. jcsd
  3. Sep 20, 2010 #2

    Doc Al

    User Avatar

    Staff: Mentor

    (1) The distance from the firefighter is given.
    (2) You don't need the height of the building, just the height of the stream as it hits the building.
     
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