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: Momentum qs

  1. Mar 25, 2010 #1
    1. The problem statement, all variables and given/known data
    A girl of mass 48kg runs toward her sationary 2.0kg skateboard and jumps on. The horizontal velocity of the girl just before she makes contact with the skateboard is 4.0m/s to the right. Disregard the effects of friction.
    a)Determine the velocity of the girl after she has landed on the skateboard.
    b)The girl then travels at this speed for a short time before jumping off, still traveling at the same speed as the skateboard. What is the velocity of the skateboard after she jumps off.

    2. Relevant equations

    (m1)(v01) + (m2)(v01) = (m1)(vf1) + (m2)(vf2)

    3. The attempt at a solution
    ok for b:
    48kg * 4.0m/s = 50kg(v2)----> is this ok to consider skateboard and girl one
    v2 =3.84m/s

    ok for c) since she jumps off and has the same velocity, that means the skateboard will also have the same velocity
  2. jcsd
  3. Mar 25, 2010 #2
    It's ok to to consider girl and skateboard as one if they have the same velocity, wich
    they have. The answer is correct
    This is OK as well.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook