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: Last Physics Word Problem, Need Help

  1. Oct 4, 2004 #1
    A man is standing at a launch site. The rocket doesn't liftoff. Frustrated s/he throws it straight up with a speed of 12.42 m/s. It is caught on the way down at a point 5.0 meters above where it was thrown, by a fellow rocketeer on the second floor, who doesn't want to see any harm come ot this wonderful rocket. The first man wants to figure out how fast the rocket was going when it was caught.
    Again thanks for all your help, really rusty with this right now.

    Any help on this one?
    Need to start with the right equation & how to solve.
  2. jcsd
  3. Oct 4, 2004 #2


    User Avatar
    Science Advisor
    Gold Member

    Make a list of what you know. Initial velocity = 12.42 m/s. Final velocity = 0 (at the top). Acceleration = 9.81 m/s^2. Use your kinmatics formulas to find the maximum height. The chapter of your book that gave you that question should have the formulas listed.

    Then figure out how far it dropped from its highest point (where velocity = 0) to the point 5 meters above the ground. (maximum height - 5). Use this new distance and another kinmatic formula to calculate the rocket's velocity at that point.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook