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!

Help- throwing apples

  1. Sep 20, 2005 #1
    Help me please I've been stuck on this problem for an hour now.....

    John throws and apple from a height of 1.3 m with velocity of 2.4 m/s. Will it reach his friend in a treehouse 5 m above the ground?

    My book gives the answer "No, it will only reach 1.6 m," but I really wanna know how to do this. Any help is greatly appreciated. Thanks!
     
  2. jcsd
  3. Sep 20, 2005 #2
    I would think you'd need to know the angle of the throw and how far away the friend is, but I'm quite a beginner so I'm not sure.
     
  4. Sep 20, 2005 #3

    Doc Al

    User Avatar

    Staff: Mentor

    Consider conservation of energy. Will the apple have enough energy to make it to that height (regardless of the angle it's thrown)?
     
  5. Sep 20, 2005 #4
    Whoops, sorry about the homework help violation....in such a rush to figure this out that I didnt see the rule.

    I'm pretty sure he wants us to use a Free Fall kinda thing, with an equation like Vf=Vi+2(a)(t), but not all those factors are there. This is basic physics stuff, we're studying like -9.81 acceleration for gravity, and how to find displacement and velocity and all that.
     
  6. Sep 20, 2005 #5

    Doc Al

    User Avatar

    Staff: Mentor

    If you threw the apple straight up at that speed, how high would it go?
     
  7. Sep 20, 2005 #6
    Well that's what the question is asking, and I assume that's displacement. Displacement in our book is

    D= .5(Vi+Vf)t

    I have Vi(2.4), and Wf would be 0 once it reached the top, but I don't know t. Am I using the wrong formula here? I have no idea what to do.... :frown:
     
  8. Sep 20, 2005 #7

    Doc Al

    User Avatar

    Staff: Mentor

    You can find the time using the definition of acceleration:
    [tex]v_f = v_i + at[/tex]
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Help- throwing apples
  1. Apple and Arrow (Replies: 1)

  2. Torque on an apple? (Replies: 1)

Loading...