# Math Help - Help with physics

1. ## Help with physics

A father (m = 94 kg) and son (m = 48 kg) are standing facing each other on a frozen pond. The son pushes on the father and finds himself moving backward at 3 m/s after they have separated. How fast will the father be moving?

Which equation is used to solve this? Can you set up the problem for me?
Thanks

2. ## Re: Help with physics

conservation of linear momentum ...

initial momentum = final momentum

$0 = m_{son}(-3 \, m/s) + m_{father} \cdot v_f$

3. ## Re: Help with physics

what is the final velocity

4. ## Re: Help with physics

Originally Posted by Louisana1
what is the final velocity
I've set up the equation and you can't figure it out?

5. ## Re: Help with physics

48(-3)+94 x vf
-50 but what is the vf in this problem. I'm still working at it

6. ## Re: Help with physics

-48(-3)/94=1.53 m/s
thx