1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Momentum of a Ball

  1. Nov 11, 2011 #1
    1. The problem statement, all variables and given/known data
    An 80 kg man standing at rest on a smooth, level ice surface throws a 200g ball horizontally with a speed of 25 m/s, relative to the Earth. a) With what speed and in what direction does the man move? b) If the man throws six such balls every 5.0s, what is the average force acting on him?

    2. Relevant equations

    3. The attempt at a solution
    I got part a using the conservation of momentum equation, but I don't get how to do b.
    Can anyone help?
  2. jcsd
  3. Nov 11, 2011 #2


    User Avatar
    Homework Helper

    Use F = ma = M*Δv/Δt
    Every throw gives him a bit of Δv. Multiply it by 6 for 6 throws.
  4. Nov 12, 2011 #3
    Okay, I got it. Thanks!
  5. Nov 12, 2011 #4


    User Avatar
    Homework Helper

    Most welcome!
  6. Nov 12, 2011 #5
    Force = rate of change of momentum
    Force = change in momentum per second
    Force = change in momentum of each interaction x number of interactions per second
    This is another way to say what Delphi51 said.
  7. Nov 12, 2011 #6
    Okay thanks!
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: Momentum of a Ball
  1. Ball Momentum (Replies: 9)

  2. Momentum of ball (Replies: 17)