Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Simple Intro Physics question

  1. Sep 7, 2005 #1
    To many this would be a simple plug it into equation problem. But for some reason this just isn't clicking for me. Here's the problem:

    An open elevator is ascending with a constant speed V of 32ft/sec. A ball is thrown straight up by a boy in the elevator when it is a height h of 100 feet above the ground. The initial speed of the ball with repect to the elevator is Vo= 64ft/sec. (A) What is the maximum height attained by the ball? (B) How long does it take for the ball to return to the elevator?

    I don't know where to start or what to plug in, please help me out, much appreciated and thanks. :frown:
  2. jcsd
  3. Sep 8, 2005 #2
    (A) [tex]\frac{64 \times 64}{2G}[/tex]
    G is the newton acceleration constant, in international units, it is [tex]9.8 meter/sec^2[/tex].
    I don't know how to convert to your unit, ft! you must convert G to ft.
    (B) [tex]\frac{64}{G}[/tex]
  4. Sep 9, 2005 #3


    User Avatar

    In physics you should use SI units anyway.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook