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: Kinetic energy lab

  1. Feb 2, 2009 #1
    I'm having some difficulty in an online class.
    Here is a screen shot for reference:
    Picture1-12.png

    1. The problem statement, all variables and given/known data:
    I'm doing a physics lab (screen shot is available above). The procedure says:
    The small object I'm using is a small pecan in it's shell.
    As you can see from the screen shot I have already recorded the time column from the experiment.
    I'm having a difficult time with kinematic velocity (because I don't understand the equation) and the kinetic energy (because the KE formula asks for mass and I do not know the mass of the almond. This lab was not specific to mass, only specific of using a small object. More specifically it says: to use a "small object (thread spool, small ball)")


    2. Relevant equations:
    Kinematic velocity = v0 + acceleration*time
    Kinetic Energy = ½mv^2 = mgh


    3. The attempt at a solution:
    I don't know how to go about either one of these. I'm sorry. The book is confusing me, too.
     
  2. jcsd
  3. Feb 2, 2009 #2

    LowlyPion

    User Avatar
    Homework Helper

    Welcome to PF.

    One thing should make it easier for you.

    The kinetic energy V doesn't depend on mass. If you will note it cancels out of both sides of the equation.

    Hence your kinetic V is (2*g*h)1/2
    Your kinematic V is simpler and is just g*t

    Be careful of your units. 1 column is m/s. The other is ft/s.
     
  4. Feb 2, 2009 #3

    tiny-tim

    User Avatar
    Science Advisor
    Homework Helper

    Welcome to PF!

    Hi McSara! Welcome to PF! :smile:

    It isn't kinematic velocity, it's a kinematic equation.

    v is just ordinary velocity. :wink:
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook