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Homework Help: Projectile Motion given only x and y distance

  1. Sep 17, 2012 #1
    1. The problem statement, all variables and given/known data
    The question reads: Luke Skywalker is dropping a bomb down a ventilation shaft on the Death Star. The circular shaft has a diameter of 1m. When the bomb is released, Luke's X-wing start-fighter is 200m above the shaft's opening and 500m horizontally from the front edge of the opening. His ship is traveling at a velocity v0 at an angle θ
    above the horizontal. If he wants the bomb to reach the front edge of the opening so that the bomb is moving toward a point on the other side of the shaft that is 10m below the opening, find the appropriate values of v0 and θ.

    2. Relevant equations
    Velocity in the y direction: vy = 10vx
    x= x0 + ((v0)(cosθ))t
    y = y0 +((v0)(sinθ))t + .5at^2

    time > 30sec
    θ > 70°
    100 < (v0) < 200 m/s

    3. The attempt at a solution
    So far I am stuck at: 200 = 4.9t^2 +10((v0)(cosθ))t. I am trying to get an equation to solve for t, but I seem to end up with two variables (v0 and θ) in one equation when I try. Please help this is due tomorrow (9-18) at 10 am!
    1. The problem statement, all variables and given/known data

    2. Relevant equations

    3. The attempt at a solution
  2. jcsd
  3. Sep 17, 2012 #2
    Maybe we try reverse position.
    The origin of frame of refrence at side of the shaft.

    y=uyt -0.5at2
    x=uxt => t=x/ux

    y=uTanθ- 0.5a(x2/(u2Cos2θ)

    2 unknowns and we have 2 points on the path equation.
    Last edited: Sep 17, 2012
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