1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Object dropped from plane - where does it land?

  1. Sep 14, 2008 #1


    User Avatar

    1. The problem statement, all variables and given/known data
    A plane is dropping an object from a height of 227m, such that it lands at a group of people on the ground. The speed of the plane is 60 m/s. How many meters before the group does the plane have to drop the object such that it lands at their position?

    2. Relevant equations
    xf = xi + vix delta t + (1/2) ax(delta t)2

    3. The attempt at a solution

    From my understanding, I need to break up the x and y components of this problem. If I can find the time it takes the object to hit the ground, I can multiply it by the plane's velocity and see what distance the plane must be from the observers for the package to hit its target.

    227 m = 9.8t m/s^2
    (227 m)/(9.8 m/s^2) = t
    t^2 = 23.162
    t = sqrt(23.162)
    t = 4.813 seconds

    Now that I have the time it took for the object to fall, I can multiply it by the plane's velocity to see how far in the x direction the object will travel in 4.813 seconds:

    4.813 s * 60 m/s = 288.78 m

    This is the answer I get, but it isn't correct. I can't see how multiplying the velocity by the time is wrong, but perhaps I have the wrong time?

  2. jcsd
  3. Sep 14, 2008 #2


    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper

    Something is wrong with that equation, since the units are different on the 2 sides:

    m ≠ s ⋅ m/s^2
    m ≠ m/s
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: Object dropped from plane - where does it land?