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

simple equation to calculate my initial velocity

  1. Jul 14, 2008 #1
    I am looking for a simple equation to calculate my initial velocity when I jump in layman's terms. For instance...if I weigh 91kg and jump 1 meter...what is my initial velocity and what would my maximum jump height be if I weighed 81kg? This is probably something I missed in freshman physics...but I was a business major and not too bright!!!
  2. jcsd
  3. Jul 14, 2008 #2
    the kinetic .5mv*v goes into Potential mgh
    so in ur example where h=1 then v is about 4.5m/s

    if you lost 10kgs and had the same jump force you would go 91/81 higher, approx 1.1m
  4. Jul 14, 2008 #3


    User Avatar

    Your initial velocity is zero and your jump height is undetermined at this point. Bodily physics is best understood by experiment, applying basic laws of motion will not ever give you a useful model.

    Do you mean maximum velocity? That can be determined easily. If you jump up a meter you jump down a meter and applying a basic law (s = ut + at^2/2) we have 1m = gt^2/2 => t = sqrt(2/g) seconds (double it for your total time in the air when jumping a meter).

    The above poster is completely correct.

    Although at 91kg, you are either an incredibly ripped individual or an alternative bodily form. In the latter case I recommend intense cycling.
    Last edited: Jul 14, 2008
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?