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!

Homework Help: What impulse was delivered to the ball by the player?

  1. Nov 16, 2007 #1
    1. The problem statement, all variables and given/known data

    A 0.47 kg soccer ball approaches a player horizontally with a velocity of 18 m/s to the north. The player strikes the ball and causes it to move in the opposite direction with a velocity of 24 m/s.

    What impulse was delivered to the ball by the player? Answer in kg*m/s

    2. Relevant equations

    impulse = change in momentum
    momentum = mv

    3. The attempt at a solution

    0.47((24-(-18)) = 19.74 kg*m/s

    or would it be

    0.47(24-18) = 2.82 kg*m/s

    i'm lost
  2. jcsd
  3. Nov 16, 2007 #2
    The change in momentum will be

    [tex]mv_1-mv_2 = m(v_1-v_2)[/tex]

    Now keep in mind these are vectors. So one will be a negative number...

    [tex].47 kg (18 - (-24) \frac{m}{s})[/tex]
  4. Nov 16, 2007 #3

    oops i meant - 2.82, it says it wrong
  5. Nov 16, 2007 #4
    Nevermind I got it

    0.47(-24-18) = -19.74 thats the answer
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook