# Momentum qs

1. Mar 25, 2010

### crosbykins

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

p0=pf
(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. Mar 25, 2010

### willem2

It's ok to to consider girl and skateboard as one if they have the same velocity, wich
they have. The answer is correct
[/QUOTE]
This is OK as well.