# Math Help - Momentum

1. ## Momentum

Hi Guys, I have question on momentum.

A 2000 kg automobile going east on chestnut street at 60mi/hr collides with a 4000kg truck which is going south across chestnut street at 20mi/hr.If they become coupled
on collision, what is the magnitude and direction of their velocity immediately after colliding?

In this case we want to use conservation of linear Momentum.But i have a struggle on their velocity because it is a vector equation, So how can i find their velocity in proper way.

2. ## Re: Momentum

can any one understand my problem?

3. ## Re: Momentum

Originally Posted by srirahulan
can any one understand my problem?
momentum is conserved in both the x and y directions

4. ## Re: Momentum

Thanks for your solution but,How can i apply the equation for that.

5. ## Re: Momentum

Originally Posted by srirahulan
Thanks for your solution but,How can i apply the equation for that.
in the x-direction ...

$p_x_0 = p_x_f$

$2000(60) = (2000+4000)v_x_f$

in the y-direction ...

$p_y_0 = p_y_f$

$4000(-20) = (2000+4000)v_y_f$

... solve for the final velocity using the equations for each component of final velocity determined by the conservation of momentum equations above.