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Homework Help: Projectile Motion/ Velocity Question

  1. Sep 6, 2009 #1
    1. The problem statement, all variables and given/known data

    You are piloting a helicopter which is rising vertically at a uniform velocity of 14.70 m/s. When you reach 196.00 m, a large object is projected with a horizontal velocity of 8.50 m/s from the rising helicopter.

    2. Relevant equations

    a) When does the ball reach ground level?
    b) Where does the ball fall horizontally relative to the helicopter’s position?
    c) What is the vertical velocity when it hits the ground?

    3. The attempt at a solution

    9.8t(squared) + 14.7t -196 = 0
  2. jcsd
  3. Sep 6, 2009 #2
    You should find the time it takes to reach the ground first.
  4. Sep 6, 2009 #3


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    Staff Emeritus
    Science Advisor
    Homework Helper

    Welcome to Physics Forums.

    It looks like you are trying to use one of the kinematic equations,

    x = xo + vot + (1/2) a t2

    However, the expression you wrote has some errors as written. You are on the right track, just be more careful in substituting values into the equation. In particular, think about whether certain quantities (position, velocity, acceleration) should be positive or negative.
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