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: Pitch Speed Revalive to Bat Speed

  1. May 20, 2007 #1
    1. The problem statement, all variables and given/known data

    It's for a physics project, in which I'm trying to calculate the velocity applied to a fastball thrown at 95mph, when the bat speed of a hitter is 86.99mph. The weight of the ball is 5oz, the weight of the bat 31oz, and we'll go with contact on the ball at .005s.(This is only the small part, the rest I can do alone)

    2. Relevant equations

    If I have the right ones...... F=ma
    Fxdelta t = mVf - mVi
    (mass1 times velocity1 + mass2 times V2)i = (mass1V1 + m2V2)f

    3. The attempt at a solution

    Just not sure where to begin.

    The only helpful site has been this http://www.kettering.edu/~drussell/bats-new/batw8.html [Broken]
    but i don't think i understand the guys explanations.

    Thanks in advance for the help.
    Last edited by a moderator: May 2, 2017
  2. jcsd
  3. May 20, 2007 #2
    Anyone? Please........
  4. May 21, 2007 #3


    User Avatar
    Gold Member

    It is difficult to solve this precisely because the ball can take spin off the bat and that drastically alters its speed and path. But if you assume a clean collision then using conservation of momentum, your 3rd formula, it is possible to estimate of the balls velocity. I thought the site you quote does it rather well. Just rearrange the formula so V1 is on the left and plug in some numbers.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook