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

Kinematics and free falling objects

  1. Sep 26, 2006 #1
    alright got a question for my homework and am stuck on it...

    here it is. If a ball is dropped from hieght H above ground and at the same instance, a ball is released from ground vertically. Determine the speeed of the second ball if the two balls are to meet at hieght of H/2 above ground.

    with that info i am stuck I know that Intial velocity of the ball dropped =0 and that to calculate it disatance h/2 will use .5at^2.

    but how to equate that to the second ball I am stuck.:confused:

    help would be apprieciated
  2. jcsd
  3. Sep 27, 2006 #2


    User Avatar

    Staff: Mentor

    Write the equation of motion for the 1st ball, showing its position as a function of time -- its motion is set, with no unknown variables. Solve for the time when the falling ball is at H/2.

    Then write the equation of motion of the 2nd ball, showing its position as a function of time, with the initial velocity as the unknown. Then solve for Vo, given that you know what time t is for it to make it to H/2.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook