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Homework Help: Projectile motion (1 question)

  1. Feb 17, 2006 #1
    A stone is prjected with a velocity of 100m/s at an elevation of 30 degrees form a tower 150m high. Find:
    a. the time of flight
    ans:12.(4) secs
    b. the horizontal distance from the tower at which the stone strikes the ground
    ans: 1.0(8) x 10 3
    c. the magnitude and the direction of the velocity of the stone striking the ground.
    Ans: 114m/s at 40(5) degrees below horizontal

  2. jcsd
  3. Feb 17, 2006 #2
    1. [tex]y = 30tsin30 - 4.9t^2 + 150[/tex]
    solve that, when y = 0.
    2. [tex]x = 30tcos30 [/tex] use the value for t that you just worked out.
    3. [tex] v_y = 30sin30 - 9.8t [/tex]
    [tex] v_x = 30cos30 [/tex]
    Solve these two, using the value of t you got in part 1, and then use pythagoras
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